Gentoo Portage Slot Conflict

admin 3/30/2022

. Repository metadata/layout.conf default 'manifest-hashes = BLAKE2B SHA512' setting, consistent with gentoo repository. Portage-2.3.19. Bug Fixes: - Bug 640934 doins: fix PYTHONPATH setting - Bug 641088 filecopy: handle EOPNOTSUPP for NFS portage-2.3.18. Bug Fixes: - Bug 640290 PORTAGEXATTREXCLUDE: add common user. attributes.
gentoo-user conflict in update. Multiple package instances within a single package slot have been pulled. And note that =sys-apps/portage-2.2 will resolve.

Gentoo Portage Slot Conflict their gaming policies, Gentoo Portage Slot Conflict therefore you will never find that as a possibility within your Gentoo Portage Slot Conflict online casino career. However, there is a possibility to try out the no deposit bonuses that come with no turnover requirements. Browse other questions tagged software-installation gentoo emerge or ask your own question. The Overflow Blog Podcast 291: Why developers are demanding more ethics in tech. If the conflict solely involves built slot-operator (foo/bar:X/Y=) dependencies (the -verbose-conflicts option can help you determine this), then you should temporarily add the emerge -pretend and -ignore-built-slot-operator-deps=y options to your emerge command, as discussed in the answer to the previous question.

< Project:Portage

How can 'blocks' between packages be resolved?

See the Blocked Packages section in the Gentoo Handbook.

Why is it that emerge does not update all packages?

By default, the dependency graph may not include some packages. For example, it will not include any packages that are listed in the output of emerge --pretend --depclean. It will also not include any build time dependencies for installed packages or binary packages. If you would like to include such build time dependencies even though they are not strictly required, use --with-bdeps=y. You can set EMERGE_DEFAULT_OPTS='--with-bdeps=y' in /etc/portage/make.conf if you would like this option to be enabled by default. If you would like a specific package to be updated in any case, you can use emerge --noreplace <atom> to have it added to the world set.

After running emerge --deep --with-bdeps=y --update @world, it is a good idea to use emerge --pretend --depclean to see if there are any packages that it would remove. If that command shows a package that you would like to keep, use emerge --noreplace <atom> to have it added to the world set.

Warning
When you use emerge --depclean to remove unwanted packages, it is a good idea to run revdep-rebuild (from the app-portage/gentoolkit package) afterward.

Note
Run man emerge to view the manual page which documents all emerge options.

How can I check for reverse dependencies of a package, to know if it can be safely uninstalled?

Run emerge --depclean --pretend --verbose [atom]... to see if there are any reverse dependencies for matched packages.

Warning
When you use emerge --depclean to remove unwanted packages, it is a good idea to run revdep-rebuild (from the app-portage/gentoolkit package) afterward.

Gentoo Portage Slot Conflict Bracket

Why does emerge --depclean sometimes remove system packages?

For system dependencies that are specified as virtuals, such as virtual/editor, it's common to have multiple packages installed that are capable of satisfying the dependency. In this case, redundant packages may be removed by emerge --depclean unless they are explicitly added to the world set. You can use emerge --noreplace <atom> to have a package added to the world set, and this will guarantee that this package will not be removed by emerge --depclean.

Why doesn't emerge account for reverse dependencies sometimes?

Complete accounting for reverse dependencies is time-consuming, and many users would be likely to complain about poor performance if this was the default behavior. So, reverse dependencies will often be neglected by dependency calculations unless the emerge --complete-graph option is enabled. You can set EMERGE_DEFAULT_OPTS='--complete-graph' in /etc/portage/make.conf if you would like this option to be enabled by default. Refer to the emerge manual page (run man emerge) for more information about the --complete-graph option.

Can I mount the Gentoo repository (/var/db/repos/gentoo) via NFS?

It is possible to share the Gentoo repository (/var/db/repos/gentoo) over NFS so that emerge --sync only needs to be run on an NFS server. However, even though NFS clients do not need to run emerge --sync, they must run emerge --metadata each time that the Portage tree is updated since otherwise their dependency calculations will slow down due to their metadata cache (located in /var/cache/edb/dep) becoming stale.

Note
With versions of Portage >=2.1.5_rc6 there is never any need to run emerge --metadata as long as the user has not enabled FEATURES='metadata-transfer' in make.conf. When metadata-transfer is disabled, metadata cache from the /var/db/repos/gentoo/metadata/md5-cache/ directory will be used directly. Run man make.conf to learn more about metadata-transfer.

If you encounter problems with an NFS setup it is important that you ensure you have the proper locking daemons on both the NFS client machines and the NFS server machine. Portage uses hardlinks over NFS in an attempt to lock files; if the locking daemon fails to lock files Portage may complain about failed or stale locks. There is a script /usr/lib/portage/bin/clean_locks that can be used to clean out old lockfiles.

Why does emerge display 'waiting for lock' messages?

The most common reason is due to FEATURES='parallel-fetch' which is enabled by default in /usr/share/portage/config/make.globals. Set FEATURES='-parallel-fetch' in /etc/portage/make.conf if you would like to disable this feature. Refer to the make.conf manual page (run man make.conf) for more information about possible FEATURES values.

If the emerge command is invoked multiple times concurrently, or if DISTDIR location is on a shared network file system, this may also trigger similar 'waiting for lock' messages. Such locks are necessary in order to prevent interference between concurrently running processes.

Why does the @preserved-rebuild set contain packages that have already been rebuilt?

This is a common problem which indicates that the build system for the given ebuild causes the package to inappropriately link against the old (preserved) version of the library, instead of the new one. As a workaround, you can manually remove the old library (such as libreadline.so.5.2) and then run revdep-rebuild in order to rebuild the packages which linked against it. A list of all preserved libraries may be obtained from portageq list_preserved_libs /.

When packages are built in parallel with the --jobs option, why aren't some packages installed immediately after they have finished building?

As a safety precaution, installation actions for system packages and their deep dependencies are executed only when no other packages are building. This behavior is required in order to avoid cases like bug #256616 (unspecified system dependencies) and bug #259954 (temporarily unsatisfied system dependencies).

Why doesn't emerge --pretend output show the correct SLOT for a package with USE=multislot enabled?

Since ebuilds that support USE=multislot violate established rules about 'constant metadata', cached SLOT value differs from the SLOT value that you will actually get once the package is installed. There is nothing portage can do about this except to implement an extension such as bug #174407.

How do I configure environment variable settings that apply only to specific packages?

Put an entry such as sys-libs/glibc debug.conf in /etc/portage/package.env, and put your variable settings in /etc/portage/env/debug.conf (using the same format as make.conf). An example debug.conf file might appear as follows:

What should I do when emerge reports a lot of dependency conflicts involving built slot-operator (foo/bar:X/Y=) dependencies?

Built slot-operator (foo/bar:X/Y=) dependencies tend to introduce a lot of noise when emerge dependency calculations fail. If you encounter this problem, then you should temporarily add the emerge --pretend and --ignore-built-slot-operator-deps=y options to your emerge command, in order to suppress noise related to built slot-operator dependencies so that it is easier to identify issues that are more important. This problem is tracked by bug #598503.

It addition to the --pretend and --ignore-built-slot-operator-deps=y options mentioned above, it can also be helpful to temporarily add --backtrack=0 to the emerge options, so that the dependency resolver does not spend extra time backtracking before it ultimately fails. Also, it can be helpful to use --ask instead of --pretend, so that emerge will ask you if you would like to write configuration changes that have been automatically generated by the --autounmask option.

Also see Built Slot Operator Dependency Conflicts.

What should I do if emerge fails to solve conflicts when there are 'no parents that aren't satisfied by other packages in this slot'?

This is a known issue, reported in bug #595224. If the conflict solely involves built slot-operator (foo/bar:X/Y=) dependencies (the --verbose-conflicts option can help you determine this), then you should temporarily add the emerge --pretend and --ignore-built-slot-operator-deps=y options to your emerge command, as discussed in the answer to the previous question. Otherwise, it may be necessary to solve the conflict by masking one of the packages with package.mask.

Why is there a dependency conflict when I attempt to upgrade a single package?

Attempts to upgrade single packages will often trigger dependency conflicts because emerge does not have an option to specify that it should automatically update reverse dependencies as needed. As discussed in bug #559354, there are plans to implement an option for automatically update of reverse dependencies. Meanwhile, the recommended practice is to update all packages together (after each emerge --sync operation), using a command such as emerge --deep --with-bdeps=y --update @world.

Retrieved from 'https://wiki.gentoo.org/index.php?title=Project:Portage/FAQ&oldid=825265'

Section: Portage (1)
Updated: Nov 2020
Index

NAME

emerge - Command-line interface to the Portage system

SYNOPSIS

ebuild: An ebuild must be, at a minimum, a valid Portagepackage directory name without a version or category, such asportage or python.Both categories and version numbers may be used in addition, suchas sys-apps/portage or =python-2.2.1-r2.emergeignores a trailing slash so that filename completion can be used.The ebuild may also be an actual filename, such as/var/db/repos/gentoo/app-admin/python/python-2.2.1-r2.ebuild.WARNING: The implementation of emerge /path/to/ebuild is broken andso this syntax shouldn't be used.
tbz2file: A tbz2file must be a valid .tbz2 created with ebuild<package>-<version>.ebuild package or emerge --buildpkg[category/]<package> or quickpkg [category/]<package>.
file: A file must be a file or directory that has been installed by one ormore packages. If an absolute path is not used, then it must begin witheither './' or '../'. For directories that are owned by multiple packages, allowning packages will be selected. See the portageq(1) owners command ifyou would like to query the owners of one or more files or directories.
set: A set is a convenient shorthand for a large group ofpackages. Six sets are currently always available: selected-packages,selected-sets, selected, system, profile, and world.selected-packages contains the user-selected 'world' packages thatare listed in /var/lib/portage/world, while selected-setscontains the nested sets that may be listed in /var/lib/portage/world_sets.system and profile both refer to sets of packages deemednecessary for your system to run properly (the differences between thesetwo sets are documented in portage(5)).selected encompasses both the selected-packagesand selected-sets sets, while world encompasses the selected,system and profile sets. (See FILES below for moreinformation.) Other sets can exist dependingon the current configuration. The default set configuration is locatedin the /usr/share/portage/config/sets directory.User sets may be created by placing files in the /etc/portage/sets/directory (see portage(5)). Note that a setis generally used in conjunction with --update. When used asarguments to emerge sets have to be prefixed with @ to berecognized. Use the --list-sets action to display a list ofavailable package sets.
atom: An atom describes bounds on a package that you wish to install.See ebuild(5) for the details on atom syntax. For example,>=dev-lang/python-2.2.1-r2 matches the latest available version ofPython greater than or equal to 2.2.1-r2. Similarly,<dev-lang/python-2.0 matches the latest available version of Pythonbefore 2.0. Note that in many shells you will need to escape characters suchas '<' and '='; use single- or double-quotes around the atomto get around escaping problems. You may also constrain an atom to match aspecific SLOT by appending a colon and a SLOT. Example:x11-libs/qt:3.

ACTIONS

No action

If no action is specified, the action is to merge in the specifiedpackages, satisfying any dependencies that they may have. Thearguments can be atoms, sets, installed files,ebuilds, or tbz2s.Note that you need to use the --usepkgoption if you want to install a tbz2. The packages are addedto the world file at the end, so that they are considered forlater updating.

--check-news

Scan all repositories for relevant unread GLEP 42 news items, and displayhow many are found. Seehttps://www.gentoo.org/glep/glep-0042.html.

--clean

Cleans up the system by examining the installed packages and removing olderpackages. This is accomplished by looking at each installed package andseparating the installed versions by slot. Clean will remove all butthe most recently installed version in each slot. Clean should notremove unslotted packages. Note: Most recently installed means mostrecent, not highest version.

--config

Run package specific actions needed to be executed after the emerge processhas completed. This usually entails configuration file setup or other similarsetups that the user may wish to run.

--depclean, -c

Cleans the system by removing packages that are not associatedwith explicitly merged packages. Depclean works by creating thefull dependency tree from the @world set,then comparing it to installed packages. Packages installed, butnot part of the dependency tree, will be uninstalled by depclean.See --with-bdeps for behavior with respect to build time dependenciesthat are not strictly required. Packages that are part of the world set willalways be kept. They can be manually added to this set with emerge--noreplace <atom>. As a safety measure, depclean will not remove anypackages unless *all* required dependencies have been resolved. As aconsequence, it is often necessary to run emerge --update --newuse--deep @world prior to depclean. Also note thatdepclean may break link level dependencies, especially when the--depclean-lib-check option is disabled. Thus, it isrecommended to use a tool such as revdep-rebuild(1)in order to detect such breakage.

WARNING:Inexperienced users are advised to use --pretend or --askwith this option in order to see a preview of which packageswill be uninstalled. Always study the list of packagesto be cleaned for any obvious mistakes. Note that packages listed inpackage.provided (see portage(5)) may be removed bydepclean, even if they are part of the world set.

Depclean serves as a dependency awareversion of --unmerge. When given one or more atoms, it willunmerge matched packages that have no reverse dependencies. Use--depclean together with --verbose to show reversedependencies.

--deselect [ y n ]

Remove atoms and/or sets from the world file. This action is impliedby uninstall actions, including --depclean,--prune and --unmerge. Use --deselect=nin order to prevent uninstall actions from removingatoms from the world file.

--help, -h

Displays help information for emerge. Adding one of the additionalarguments listed above will give you more specific help informationon that subject. The internal emerge help documentation isupdated more frequently than this man page; check it out if youare having problems that this man page does not help resolve.

--info

Produces a list of information to include in bug reports which aids thedevelopers when fixing the reported problem. Please include thisinformation when submitting a bug report. Expanded output can be obtainedwith the --verbose option.

--list-sets

Displays a list of available package sets.

--metadata

Transfers pregenerated metadata cache from ${repository_location}/metadata/md5-cache/to /var/cache/edb/dep/ as is normally done on the tail end of an rsync update usingemerge --sync. This process populates the cache database that Portage usesfor pre-parsed lookups of package data. It does not populate cache for repositoriesnot distributing pregenerated metadata cache. In order to generate cache for theserepositories, use --regen.In versions of portage >=2.1.5 the --metadata action is totally unnecessaryunless the user has enabled FEATURES='metadata-transfer' in make.conf(5).

--prune, -P

Removes all but the highest installed version of a package from yoursystem. Use --prune together with --verbose to showreverse dependencies or with --nodeps to ignore all dependencies.WARNING: This action can remove packages from your world file! Checkthe emerge output of the next --depclean run carefully! Use--depclean to avoid this issue.

--regen

Causes portage to check and update the dependency cache of all ebuilds in therepository. The cache is used to speed up searches and the building ofdependency trees. This command is not recommended for rsync users as rsyncupdates the cache using server-side caches. If you do not know thedifferences between a 'rsync user' and some other user, then you are a 'rsyncuser' :). Rsync users should simply run emerge --sync to regeneratethe cache. After a portage update, rsync users may find it convenient to runemerge --metadata to rebuild the cache as portage does at the end ofa sync operation. In order to specify parallel --regen behavior, usethe --jobs and --load-average options. If you would like togenerate and distribute cache for use by others, use egencache(1).

--resume, -r

Resumes the most recent merge list that has been aborted due to an error.This re-uses the arguments and options that were given with the originalcommand that's being resumed, and the user may also provideadditional options when calling --resume. It is an error to provideatoms or sets as arguments to --resume, since the arguments from theresumed command are used instead.Please note that this operation will only return an error on failure. If thereis nothing for portage to do, then portage will exit with a message and asuccess condition. A resume list will persist until it has been completed inentirety or until another aborted merge list replaces it. The resume historyis capable of storing two merge lists. After one resume list completes, it ispossible to invoke --resume once again in order to resume an older list.The resume lists are stored in /var/cache/edb/mtimedb, and may beexplicitly discarded by running `emaint --fix cleanresume` (seeemaint(1)).

--search, -s

Searches for matches of the supplied string in the ebuild repository.By default emerge uses a case-insensitive simple search, but you canenable a regular expression search by prefixing the search string with %(the % prefix can often be omitted if the--regex-search-auto option is enabled).For example, emerge --search '%^kde' searches for any package whosename starts with 'kde'; emerge --search '%gcc$' searches for anypackage that ends with 'gcc'; emerge --search 'office' searches forany package that contains the word 'office'. If you want to include thecategory into the search string, prepend an @: emerge --search'%@^dev-java.*jdk'. If you want to search the package descriptions as well,use the --searchdesc action.

--searchdesc, -S

Matches the search string against the description field as well asthe package name. Take caution as the descriptions are alsomatched as regular expressions.

--sync

Updates repositories, for which auto-sync, sync-type and sync-uri attributes areset in repos.conf. A list of repos or aliases can be specified, in which casethey will be updated regardless of their auto-sync attribute. Seeportage(5) for more information.The PORTAGE_SYNC_STALE variable configureswarnings that are shown when emerge --sync has notbeen executed recently.

WARNING:The emerge --sync action will revert local changes (e.g. modifications oradditions of files) inside repositories synchronized using rsync.

NOTE:The emerge --sync command is a compatibility command. Sync operations arenow performed using the new emaint sync module. This new emaint sync modulehas greater functionality and flexibility. Please refer to emaint(1) formore information about sync operations.

NOTE:The emerge-webrsync program will download the entireebuild repository as a tarball, which is much faster than emerge--sync for first time syncs.

--unmerge, -C

WARNING: This action can remove important packages! Removesall matching packages following a counter governed by CLEAN_DELAY.This does no checking of dependencies, so it may remove packages necessaryfor the proper operation of your system. Its arguments can be atomsor ebuilds. For a dependency aware version of --unmerge, use--depclean or --prune. For a version withCLEAN_DELAY=0, use --rage-clean.

--version, -V

Displays the version number of emerge.

OPTIONS

--accept-properties=ACCEPT_PROPERTIES

This option temporarily overrides the ACCEPT_PROPERTIESvariable. The ACCEPT_PROPERTIES variable is incremental,which means that the specified setting is appended to theexisting value from your configuration. The special -*token can be used to discard the existing configurationvalue and start fresh. See the MASKED PACKAGES sectionand make.conf(5) for more information aboutACCEPT_PROPERTIES. A typical usage example for this optionwould be to use --accept-properties=-interactive totemporarily mask interactive packages. With defaultconfiguration, this would result in an effectiveACCEPT_PROPERTIES value of '* -interactive'.

--accept-restrict=ACCEPT_RESTRICT

This option temporarily overrides the ACCEPT_RESTRICTvariable. The ACCEPT_RESTRICT variable is incremental,which means that the specified setting is appended to theexisting value from your configuration. The special -*token can be used to discard the existing configurationvalue and start fresh. See the MASKED PACKAGES sectionand make.conf(5) for more information aboutACCEPT_RESTRICT. A typical usage example for this optionwould be to use --accept-restrict=-bindist totemporarily mask packages that are not binaryre-distributable. With defaultconfiguration, this would result in an effectiveACCEPT_RESTRICT value of '* -bindist'.

--alert [ y n ], -A

Add a terminal bell character ('a') to all interactive prompts. Thisis especially useful if dependency resolution is taking a long time, andyou want emerge to alert you when it is finished. If you useemerge -auAD world, emerge will courteously point out when it hasfinished calculating the graph. Gentoo emerge slot conflict

--alert may be 'y' or 'n'. 'true' and 'false' mean the same thing.Using --alert without an option is the same as using it with 'y'.Try it with 'emerge -aA sys-apps/portage'.

If your terminal emulator is set up to make 'a' into a window managerurgency hint, move your cursor to a different window to get the effect.

--alphabetical

When displaying USE and other flag output, combines the enabled anddisabled lists into one list and sorts the whole list alphabetically.

--ask [ y n ], -a

Before performing the action, display what will take place (server info for--sync, --pretend output for merge, and so forth), then askwhether to proceed with the action or abort. Using --ask is moreefficient than using --pretend and then executing the same commandwithout --pretend, as dependencies will only need to be calculatedonce. WARNING: If the 'Enter' key is pressed at the prompt (with no otherinput), it is interpreted as acceptance of the first choice. Note that theinputbuffer is not cleared prior to the prompt, so an accidental press of the'Enter' key at any time prior to the prompt will be interpreted as a choice!Use the --ask-enter-invalid option if you want a single 'Enter' keypress to be interpreted as invalid input.

--ask-enter-invalid

When used together with the --ask option,interpret a single 'Enter' key press asinvalid input. This helps prevent accidentalacceptance of the first choice. This option isintended to be set in the make.conf(5)EMERGE_DEFAULT_OPTS variable.

--autounmask [ y n ]

Automatically unmask packages and generate package.usesettings as necessary to satisfy dependencies. This optionis disabled by default, except for portions of behaviorwhich are controlled by the --autounmask-use and--autounmask-license options (--autounmask=ndisables autounmask behavior entirely). If any configurationchanges are required, then they will be displayedafter the merge list and emerge will immediatelyabort. If the displayed configuration changes aresatisfactory, you should copy and paste them intothe specified configuration file(s), or enable the--autounmask-write option. TheEMERGE_DEFAULT_OPTS variable may be used to entirelyenable or disable this option by default in make.conf(5).

--autounmask-backtrack < y n >

Allow backtracking after autounmask has detected thatconfiguration changes are necessary. This option is notrecommended, since it can cause a large amount of time tobe wasted by backtracking calculations, even though thereis no guarantee that it will produce a solution. Thisoption is disabled by default.

--autounmask-continue [ y n ]

Automatically apply autounmask changes to configurationfiles, and continue to execute the specified command. Ifthe dependency calculation is not entirely successful, thenemerge will simply abort without modifying any configurationfiles. This option implies --autounmask-backtrack=y.WARNING:This option is intended to be used only with great caution,since it is possible for it to make nonsensical configurationchanges which may lead to system breakage. Therefore, it isadvisable to use --ask together with this option.

--autounmask-only [ y n ]

Instead of doing any package building, just unmaskpackages and generate package.use settings as necessaryto satisfy dependencies. This option is disabled bydefault.

--autounmask-unrestricted-atoms [ y n ]

If --autounmask is enabled, keyword and mask changesusing the '=' operator will be written. With thisoption, '>=' operators will be used whenever possible.USE and license changes always use the latter behavior.

--autounmask-keep-keywords [ y n ]

If --autounmask is enabled, no package.accept_keywords changes willbe created. This leads to unsatisfied dependencies if any keywordchanges are required. This option does not imply --autounmask-keep-masks,so --autounmask is still allowed to create package.unmask changes unlessthe --autounmask-keep-masks is also specified.

--autounmask-keep-masks [ y n ]

If --autounmask is enabled, no package.unmask or ** keyword changeswill be created. This leads to unsatisfied dependencies ifno other solution exists.

--autounmask-license < y n >

Allow autounmask package.license changes. This option is enabled by default(either --autounmask=n or --autounmask-license=n disablesit). The EMERGE_DEFAULT_OPTS variable may be used todisable this option by default in make.conf(5).

--autounmask-use < y n >

Allow autounmask package.use changes. This option is enabled by default(either --autounmask=n or --autounmask-use=n disablesit). The EMERGE_DEFAULT_OPTS variable may be used todisable this option by default in make.conf(5).

--autounmask-write [ y n ]

If --autounmask is enabled, changes are writtento config files, respecting CONFIG_PROTECT and --ask.If the corresponding package.* is a file, the changes are appended toit, if it is a directory, changes are written to the lexicographicallylast file. This way it is always ensured that the new changes takeprecedence over existing changes. This option is automatically enabled with--ask.

--backtrack=COUNT

Specifies an integer number of times to backtrack ifdependency calculation fails due to a conflict or anunsatisfied dependency (default: '10').

--binpkg-changed-deps [ y n ]

Tells emerge to ignore binary packages for which the correspondingebuild dependencies have changed since the packages were built.In order to help avoid issues with resolving inconsistent dependencies,this option is automatically enabled unless the --usepkgonlyoption is enabled. Behavior with respect to changed build-timedependencies is controlled by the --with-bdeps option.

--binpkg-respect-use [ y n ]

Tells emerge to ignore binary packages if their USE flagsdon't match the current configuration. In order to help avoid issueswith resolving inconsistent USE flag settings, this option isautomatically enabled unless the --usepkgonly optionis enabled.

--buildpkg [ y n ], -b

Tells emerge to build binary packages for all ebuilds processed inaddition to actually merging the packages. Useful for maintainersor if you administrate multiple Gentoo Linux systems (build once,emerge tbz2s everywhere) as well as disaster recovery. The packagewill be created in the PKGDIR directory (see make.conf(5)).An alternative for already-mergedpackages is to use quickpkg(1) which creates a tbz2 from thelive filesystem.

--buildpkg-exclude ATOMS

A space separated list of package atoms for whichno binary packages should be built. This option overrides allpossible ways to enable building of binary packages except forthe downgrade-backup and unmerge-backup FEATURES settings (seemake.conf(5) for more information about FEATURES settings).

--buildpkgonly, -B

Creates binary packages for all ebuilds processed without actuallymerging the packages. This comes with the caveat that all build-timedependencies must already be emerged on the system.

--changed-deps [ y n ]

Tells emerge to replace installed packages for which the correspondingebuild dependencies have changed since the packages were built. Thisoption also implies the --selective option. Behavior withrespect to changed build-time dependencies is controlled by the--with-bdeps option.

--changed-deps-report [ y n ]

Tells emerge to report ebuilds for which the ebuild dependencies havechanged since the installed instance was built. Behavior with respect tochanged build-time dependencies is controlled by the--with-bdeps option.

--changed-slot [ y n ]

Tells emerge to replace installed packages for which the correspondingebuild SLOT metadata has changed since the packages were built. Thisoption also implies the --selective option. This may also resultin rebuilds for any installed packages that have slot/sub-slot :=operator dependencies that are sensitive to the relevant SLOT metadata.

--changed-use, -U

Tells emerge to include installed packages where USE flags havechanged since installation. This option also implies the--selective option. Unlike --newuse, the--changed-use option does not trigger reinstallation whenflags that the user has not enabled are added or removed.

NOTE: This option ignores the state of the 'test' USE flag, since that flaghas a special binding to FEATURES='test' (see make.conf(5) for moreinformation about FEATURES settings).

--color < y n >

Enable or disable color output. This option will override NOCOLOR(see make.conf(5)) and may also be used to force color output when stdoutis not a tty (by default, color is disabled unless stdout is a tty).

--columns

Used alongside --pretend to cause the package name, new version,and old version to be displayed in an aligned format for easy cut-n-paste.

--complete-graph [ y n ]

This causes emerge to consider the deep dependencies of allpackages from the world set. With this option enabled,emerge will bail out if it determines that the given operation willbreak any dependencies of the packages that have been added to thegraph. Like the --deep option, the --complete-graphoption will significantly increase the time taken for dependencycalculations. Note that, unlike the --deep option, the--complete-graph option does not cause any more packages tobe updated than would have otherwise been updated with the option disabled.Using --with-bdeps=y together with --complete-graph makesthe graph as complete as possible.

--complete-graph-if-new-use < y n >

Trigger the --complete-graph behavior if USE or IUSE willchange for an installed package. This option is enabled by default.

--complete-graph-if-new-ver < y n >

Trigger the --complete-graph behavior if an installed packageversion will change (upgrade or downgrade). This option is enabled by default.

--config-root=DIR

Set the PORTAGE_CONFIGROOT environment variable.

--debug, -d

Tells emerge to run the emerge command in --debug mode. In thismode the bash build environment will run with the -x option, causingit to output verbose debugging information to stdout. This also enablesa plethora of other output (mostly dependency resolution messages).

--deep [DEPTH], -D

This flag forcesemerge to consider the entire dependency tree of packages,instead of checking only the immediate dependencies of the packages.As an example, this catches updates in libraries that are not directlylisted in the dependencies of a package. Also see --with-bdeps forbehavior with respect to build time dependencies that are not strictlyrequired.

--depclean-lib-check [ y n ]

Account for library link-level dependencies during--depclean and --prune actions.This option is enabled by default. If FEATURES='preserve-libs' isenabled in make.conf(5), and preserve-libs is not restrictedfor any of the packages selected for removal, then this option isignored because any libraries that have consumers will simply bepreserved.

--digest

Prevent corruption from being noticed. The `repoman manifest` command is thepreferred way to generate manifests and it is capable of doing an entirerepository or category at once (see repoman(1)).

--dynamic-deps < y n >

In dependency calculations, substitute the dependencies of installedpackages with the dependencies of corresponding unbuilt ebuilds fromsource repositories. This causes the effective dependencies ofinstalled packages to vary dynamically when source ebuild dependenciesare modified. This option is enabled by default.

WARNING:If you want to disable --dynamic-deps, then it may be necessary tofirst run fixpackages(1) in order to get the best results. Thefixpackages(1) command performs two different operations that canalso be performed separately by the `emaint --fix moveinst` and`emaint --fix movebin` commands (see emaint(1)).

--emptytree, -e

Reinstalls target atoms and their entire deepdependency tree, as though no packages are currentlyinstalled. You should run this with --pretendfirst to make sure the result is what you expect.

--exclude ATOMS

A space separated list of package names or slot atoms.Emerge won't install any ebuild or binary package thatmatches any of the given package atoms.

--fail-clean [ y n ]

Clean up temporary files after a build failure. This isparticularly useful if you have PORTAGE_TMPDIR ontmpfs. If this option is enabled, you probably also wantto enable PORTAGE_LOGDIR (see make.conf(5)) inorder to save the build log.

--fetchonly, -f

Instead of doing any package building, just perform fetches for allpackages (fetch things from SRC_URI based upon USE setting).

--fetch-all-uri, -F

Instead of doing any package building, just perform fetches for allpackages (fetch everything in SRC_URI regardless of USE setting).

--fuzzy-search [ y n ]

Enable or disable fuzzy search for search actions. When fuzzy searchis enabled, a result is returned if it is sufficiently similar to thesearch string, without requiring an exact match. This option is enabledby default. Fuzzy search does not support regular expressions, thereforeit is automatically disabled for regular expression searches. Fuzzysearch is slightly slower than non-fuzzy search.

--getbinpkg [ y n ], -g

Using the server and location defined in PORTAGE_BINHOST (seemake.conf(5)), portage will download the information from each binarypackage found and it will use that information to help build the dependencylist. This option implies -k. (Use -gK for binary-onlymerging.)

--getbinpkgonly [ y n ], -G

This option is identical to -g, as above, except binaries from theremote server are preferred over local packages if they are not identical.

--ignore-default-opts

Causes EMERGE_DEFAULT_OPTS (see make.conf(5)) to be ignored.

--ignore-built-slot-operator-deps < y n >

Ignore the slot/sub-slot := operator parts of dependencies that havebeen recorded when packages where built. This option is intendedonly for debugging purposes, and it only affects built packagesthat specify slot/sub-slot := operator dependencies which aresupported beginning with EAPI 5.

--ignore-soname-deps < y n >

Ignore the soname dependencies of binary and installed packages. Thisoption is enabled by default, since soname dependencies are relativelynew, and the required metadata is not guaranteed to exist for binary andinstalled packages built with older versions of portage. Also, sonamedependencies will be automatically ignored for dependency calculationsthat can pull unbuilt ebuilds into the dependency graph, since unbuiltebuilds do not have any soname dependency metadata, making it impossibleto determine whether an unresolved soname dependency can be satisfied.Therefore, --usepkgonly (or --getbinpkgonly) must beused in order to enable soname depedency resolution when installingpackages.

--ignore-world [ y n ]

Ignore the @world package set and its dependencies. This may be usefulif there is a desire to perform an action even though it might breakthe dependencies of some installed packages (it might also removeinstalled packages in order to solve blockers). This also alters thebehavior of --complete-graph options so that only deepdependencies of packages given as arguments are included in thedependency graph. This option may be useful as an alternative to--nodeps in cases where it is desirable to account fordependencies of packages given as arguments.

WARNING:This option is intended to be used only with great caution, since it ispossible for it to make nonsensical changes which may lead to systembreakage. Therefore, it is advisable to use --ask together withthis option.

--implicit-system-deps < y n >

Assume that packages may have implicit dependencies on packages whichbelong to the @system set. This option is enabled by default. One of theeffects of disabling this option is to allow the --jobs option tospawn jobs without accounting for the possiblity of implicit dependencieson packages that belong to the @system set.

-j [JOBS], --jobs[=JOBS]

Specifies the number of packages to build simultaneously. If this option isgiven without an argument, emerge will not limit the number of jobs that canrun simultaneously. Also see the related --load-average option.Similarly to the --quiet-build option, the --jobs option causes allbuild output to be redirected to logs.Note that interactive packages currently force a settingof --jobs=1. This issue can be temporarily avoidedby specifying --accept-properties=-interactive.

--keep-going [ y n ]

Continue as much as possible after an error. When an error occurs,dependencies are recalculated for remaining packages and any withunsatisfied dependencies are automatically dropped. Also seethe related --skipfirst option.

-l [LOAD], --load-average[=LOAD]

Specifies that no new builds should be started if there are other buildsrunning and the load average is at least LOAD (a floating-point number).With no argument, removes a previous load limit.This option is recommended for use in combination with --jobs inorder to avoid excess load. See make(1) for information aboutanalogous options that should be configured via MAKEOPTS inmake.conf(5).

--misspell-suggestions < y n >

Enable or disable misspell suggestions. By default, emerge will showa list of packages with similar names when a package doesn't exist.The EMERGE_DEFAULT_OPTS variable may be used to disable thisoption by default.

--newrepo

Tells emerge to recompile a package if it is now being pulled from adifferent repository. This option also implies the--selective option.

Gentoo Portage Slot Conflict Buster

--newuse, -N

Tells emerge to include installed packages where USEflags have changed since compilation. This optionalso implies the --selective option.USE flag changes include:

A USE flag was added to a package.A USE flag was removed from a package.A USE flag was turned on for a package.A USE flag was turned off for a package.

USE flags may be toggled by your profile as well as your USE and package.usesettings. If you would like to skip rebuilds for which disabled flags havebeen added to or removed from IUSE, see the related--changed-use option. If you would like to skip rebuilds forspecific packages, see the --exclude option.

NOTE: This option ignores the state of the 'test' USE flag, since that flaghas a special binding to FEATURES='test' (see make.conf(5) for moreinformation about FEATURES settings).

--noconfmem

Causes portage to disregard merge records indicating that a config fileinside of a CONFIG_PROTECT directory has been merged already. Portagewill normally merge those files only once to prevent the user fromdealing with the same config multiple times. This flag will cause thefile to always be merged.

--nodeps, -O

Merges specified packages without merging any dependencies. Note thatthe build may fail if the dependencies aren't satisfied.

--noreplace, -n

Skips the packages specified on the command-line that have alreadybeen installed. Without this option, any package atoms or package setsyou specify on the command-line will cause Portage to remergethe package, even if it is already installed. Note that Portage willnot remerge dependencies by default. This option can be used to update theworld file without rebuilding the packages.

--nospinner

Disables the spinner for the session. The spinner is active when theterminal device is determined to be a TTY. This flag disables it regardless.

--usepkg-exclude ATOMS

A space separated list of package names or slot atoms. Emerge will ignorematching binary packages.

--rebuild-exclude ATOMS

A space separated list of package names or slot atoms. Emerge will not rebuildmatching packages due to --rebuild.

--rebuild-ignore ATOMS

A space separated list of package names or slot atoms. Emerge will not rebuildpackages that depend on matching packages due to --rebuild.

--regex-search-auto < y n >

Enable or disable automatic regular expression detection for search actions.If this option is enabled (the default), then regular expression searchis automatically enabled when the search string is a valid regular expressionwhich contains any of these commonly used regular expression characters orcharacter sequences:^ $ * [ ] { } ? .+

--oneshot, -1

Emerge as normal, but do not add the packages to the world filefor later updating.

WARNING: This option should only be used for packages that arereachable from the @world package set (those that would not be removedby --depclean), since dependencies of unreachable packages areallowed to be broken when satisfying dependencies of other packages.Broken dependencies of this sort will invalidate assumptions that makeit possible for --deep to be disabled by default.

--onlydeps, -o

Only merge (or pretend to merge) the dependencies of the packagesspecified, not the packages themselves.

--onlydeps-with-rdeps < y n >

Include run time dependencies when --onlydeps is specified.When this is disabled only build time dependencies are included. Thisoption is enabled by default.

--package-moves [ y n ]

Perform package moves when necessary. This option is enabledby default. Package moves are typically applied immediatelyafter a --sync action. They are applied in anincremental fashion, using only the subset of the history ofpackage moves which have been added or modified since theprevious application of package moves.

WARNING: This optionshould remain enabled under normal circumstances.Do not disable it unless you know what you aredoing.

NOTE: The fixpackages(1) command can be used toexhaustively apply the entire history of package moves,regardless of whether or not any of the package moves havebeen previously applied.

--pkg-format

Specify which binary package format will be created as target.Possible choices now are tar and rpm or their combinations.

--prefix=DIR

Set the EPREFIX environment variable.

--pretend, -p

Instead of actually performing the merge, simply display what *would*have been installed if --pretend weren't used. Using --pretendis strongly recommended before installing an unfamiliar package. Inthe printout:

N	new (not yet installed)
S	new SLOT installation (side-by-side versions)
U	updating (to another version)
D	downgrading (best version seems lower)
r	reinstall (forced for some reason, possibly due to slot or sub-slot)
R	replacing (remerging same version)
F	fetch restricted (must be manually downloaded)
f	fetch restricted (already downloaded)
I	interactive (requires user input)
B	blocked by another package (unresolved conflict)
b	blocked by another package (automatically resolved conflict)

--quickpkg-direct < y n >

Enable use of installed packages directly as binary packages. This issimilar to using binary packages produced by quickpkg(1), butinstalled packages are used directly as though they are binary packages.If --quickpkg-direct-root=DIR is not also set to somethingother than '/', then --root=DIR must be used,and it comes with the caveat that packages are only allowed to beinstalled into the root that is specified by the --root=DIRoption (the other root which serves as a source of packages isassumed to be immutable during the entire operation).

Default behavior for handling of protected configuration files iscontrolled by the QUICKPKG_DEFAULT_OPTS variable. The relevantquickpkg options are --include-config and--include-unmodified-config (refer to the quickpkg(1)man page). When a configuration file is not included because it isprotected, an ewarn message is logged.

--quickpkg-direct-root=DIR

Specify the root to use as the --quickpkg-direct package source.This root is assumed to be immutable during the entire emerge operation.The default is set to '/'.

--quiet [ y n ], -q

Results may vary, but the general outcome is a reduced or condensedoutput from portage's displays.

--quiet-build [ y n ]

Redirect all build output to logs alone, and do not display it onstdout. If a build failure occurs for a single package, the buildlog will be automatically displayed on stdout (unless the--quiet-fail option is enabled). If there are multiplebuild failures (due to options like --keep-going or --jobs),then the content of the log files will not be displayed, and insteadthe paths of the log files will be displayed together with thecorresponding die messages.Note that interactive packages currently force all build output tobe displayed on stdout. This issue can be temporarily avoidedby specifying --accept-properties=-interactive.Further, note that disabling --quiet-build has no effect if--jobs is set to anything higher than 1.

--quiet-fail [ y n ]

Suppresses display of the build log on stdout when build output is hiddendue to options such as --jobs, --quiet, or--quiet-build. Only the die message and the path of the build logwill be displayed on stdout.

--quiet-repo-display

In the package merge list display, suppress ::repository output, andinstead use numbers to indicate which repositories package come from.

--quiet-unmerge-warn

Disable the warning message that's shown prior to--unmerge actions. This option is intendedto be set in the make.conf(5)EMERGE_DEFAULT_OPTS variable.

--rage-clean

WARNING: This action can remove important packages!--rage-clean does --unmerge with CLEAN_DELAY=0.

--read-news [ y n ]

Offer to read news via eselect if there are unread news. This optionhas no effect unless --ask is enabled.

--rebuild-if-new-slot [ y n ]

Automatically rebuild or reinstall packages when slot/sub-slot :=operator dependencies can be satisfied by a newer slot, so thatolder packages slots will become eligible for removal by the--depclean action as soon as possible. This option onlyaffects packages that specify slot/sub-slot := dependencieswhich are supported beginning with EAPI 5.Since this option requireschecking of reverse dependencies, it enables --complete-graphmode whenever a new slot is installed. This option is enabled bydefault.

NOTE: If you want to skip all rebuilds involving slot-operatordependecies (including those that involve sub-slot changes alone),then --ignore-built-slot-operator-deps=y is the optionthat you are looking for, since --rebuild-if-new-slotdoes not affect rebuilds triggered by sub-slot changes alone.

--rebuild-if-new-rev [ y n ]

Rebuild packages when build-time dependencies are built from source, if thedependency is not already installed with the same version and revision.

--rebuild-if-new-ver [ y n ]

Rebuild packages when build-time dependencies are built from source, if thedependency is not already installed with the same version. Revision numbersare ignored.

--rebuild-if-unbuilt [ y n ]

Rebuild packages when build-time dependencies are built from source.

--rebuilt-binaries [ y n ]

Replace installed packages with binary packages that havebeen rebuilt. Rebuilds are detected by comparison ofBUILD_TIME package metadata. This option is enabledautomatically when using binary packages(--usepkgonly or --getbinpkgonly) together with--update and --deep.

--rebuilt-binaries-timestamp=TIMESTAMP

This option modifies emerge's behaviour only if--rebuilt-binaries is given. Only binaries thathave a BUILD_TIME that is larger than the given TIMESTAMPand that is larger than that of the installed package willbe considered by the rebuilt-binaries logic.

--reinstall changed-use

This is an alias for --changed-use.

--reinstall-atoms ATOMS

A space separated list of package names or slot atoms. Emerge will treatmatching packages as if they are not installed, and reinstall them ifnecessary.

--root=DIR

Set the ROOT environment variable.

--sysroot=DIR

Set the SYSROOT environment variable.

--root-deps[=rdeps]

If no argument is given then build-time dependencies of packages forROOT are installed to ROOT instead of /.If the rdeps argument is given then discard all build-time dependenciesof packages for ROOT

Gentoo Emerge Slot Conflict

.This option is only meaningful when used together with ROOT and it shouldnot be enabled under normal circumstances!

Does not affect EAPIs that support BDEPEND. EAPI 7 introducesBDEPEND as a means to adjust installation into / and ROOT. Usethe SYSROOT environment variable to control where DEPENDis installed to under EAPI 7.

When ebuilds with different EAPIs feature in the same emerge run, theappropriate behaviour for each EAPI is applied independently to eachebuild.

--search-index < y n >

Enable or disable indexed search for search actions. This option isenabled by default. The search index needs to be regenerated byegencache(1) after changes are made to a repository (see the--update-pkg-desc-index action). This setting can be addedto EMERGE_DEFAULT_OPTS (see make.conf(5)) and lateroverridden via the command line.

--search-similarity PERCENTAGE

Set the minimum similarity percentage (a floating-point number between0 and 100). Search results with similarity percentages lower than thisare discarded (default: '80'). This option has no effect unless the--fuzzy-search option is enabled.

--select [ y n ], -w

Add specified packages to the world set (inverse of--oneshot). This is useful if you want touse EMERGE_DEFAULT_OPTS to make--oneshot behavior default.

--selective [ y n ]

This is identical to the --noreplace option.Some options, such as --update, imply --selective.Use --selective=n if you want to forcefully disable--selective, regardless of options like --changed-use,--newuse, --noreplace, or --update.

--skipfirst

This option is only valid when used with --resume. It removes thefirst package in the resume list. Dependencies are recalculated forremaining packages and any that have unsatisfied dependencies or aremasked will be automatically dropped. Also see the related--keep-going option.

--sync-submodule <glsa news profiles>

Restrict sync to the specified submodule(s). This option may bespecified multiple times, in order to sync multiple submodules.Currently, this option has no effect for sync protocols otherthan rsync.(--sync action only)

--tree, -t

Shows the dependency tree for the given target by indenting dependencies.This is only really useful in combination with --emptytree or--update and --deep.

--unordered-display

By default the displayed merge list is sorted using theorder in which the packages will be merged. When--tree is used together with this option, thisconstraint is removed, hopefully leading to a morereadable dependency tree.

--update, -u

Updates packages to the best version available, which maynot always be the highest version number due to maskingfor testing and development. Package atoms specified onthe command line are greedy, meaning that unspecificatoms may match multiple versions of slotted packages.This option also implies the --selective option.

--use-ebuild-visibility [ y n ]

Use unbuilt ebuild metadata for visibilitychecks on built packages.

--useoldpkg-atoms ATOMS

A space separated list of package names or slot atoms. Emerge will prefermatching binary packages over newer unbuilt packages.

--usepkg [ y n ], -k

Tells emerge to use binary packages (from $PKGDIR) if they are available, thuspossibly avoiding some time-consuming compiles. This option is useful for CDinstalls; you can export PKGDIR=/mnt/cdrom/packages and then use this option tohave emerge 'pull' binary packages from the CD in order to satisfydependencies.

--usepkgonly [ y n ], -K

Tells emerge to only use binary packages (from $PKGDIR). All the binarypackages must be available at the time of dependency calculation or emergewill simply abort. Portage does not use ebuild repositories when calculatingdependency information so all masking information is ignored.

--verbose [ y n ], -v

Tell emerge to run in verbose mode. Currently this flag causes emerge to printout GNU info errors, if any, and to show the USE flags that will be used foreach package when pretending. The following symbols are affixed to USE flagsin order to indicate their status:

Symbol	Location	Meaning
-	prefix	not enabled (either disabled or removed)
*	suffix	transition to or from the enabled state
%	suffix	newly added or removed
()	circumfix	forced, masked, or removed
{}	circumfix	state is bound to FEATURES settings

--verbose-conflicts

Make slot conflicts more verbose. Note that this may in some cases outputhundreds of packages for slot conflicts.

--verbose-slot-rebuilds [ y n ]

Turns on/off the extra emerge output to list which packages are causing rebuilds.The default is set to 'y' (on).

--with-bdeps < y n >

In dependency calculations, pull in build time dependenciesthat are not strictly required. This option is automatically enabled forinstallation actions, meaning they will be installed, and defaults toaqyaq for the --depclean action, meaning they will not beremoved. In order to prevent the --with-bdeps option from beingautomatically enabled for installation actions, specify--with-bdeps-auto=n in either the command line orEMERGE_DEFAULT_OPTS.

Since many users of binary packages do not want unnecessary build timedependencies installed, this option is not automatically enabled forinstallation actions when the --usepkg option is enabled. Inorder to pull in build time dependencies for binary packages with--usepkg, --with-bdeps=y must be specified explicitly.This also applies to options that enable the --usepkg optionimplicitly, such as --getbinpkg.

This setting can be added toEMERGE_DEFAULT_OPTS (see make.conf(5)) and later overridden via thecommand line.

--with-bdeps-auto < y n >

This option is used to enable or disable the program logic that causes--with-bdeps is to be automatically enabled for installationactions. This option is enabled by default. Use--with-bdeps-auto=n to prevent --with-bdeps frombeing automatically enabled for installation actions. This setting canbe added to EMERGE_DEFAULT_OPTS (see make.conf(5)) and lateroverridden via the command line.

NOTE: The program logic that causes --with-bdeps to beautomatically enabled for installation actions does not affect removalactions such as the --depclean action. Therefore, when--with-bdeps-auto=n is specified in EMERGE_DEFAULT_OPTS,it does not affect the default --with-bdeps=y setting thatapplies to the --depclean action. The default--with-bdeps=y setting that applies to the --depcleanaction can be overridden only by specifying --with-bdeps=n.

--with-test-deps [ y n ]

For packages matched by arguments, this option will pull in dependenciesthat are conditional on the 'test' USE flag, even if 'test' is notenabled in FEATURES for the matched packages. (see make.conf(5)for more information about FEATURES settings).

ENVIRONMENT OPTIONS

[ebuild R ] sys-apps/sed-4.0.5: Sed 4.0.5 has already been emerged, but if you run the command, thenportage will Re-emerge the specified package (sed in this case).
[ebuild F ] media-video/realplayer-8-r6: The realplayer package requires that you Fetch the sources manually.When you attempt to emerge the package, if the sources are not found,then portage will halt and you will be provided with instructions on howto download the required files.
[ebuild f ] media-video/realplayer-8-r6: The realplayer package's files are already downloaded.
[ebuild U ] net-fs/samba-2.2.8_pre1 [2.2.7a]: Samba 2.2.7a has already been emerged and can be Updated to version2.2.8_pre1.
[ebuild UD] media-libs/libgd-1.8.4 [2.0.11]: Libgd 2.0.11 is already emerged, but if you run the command, thenportage will Downgrade to version 1.8.4 for you.
This may occur if a newer version of a package has been masked because it isbroken or it creates a security risk on your system and a fix has not beenreleased yet.
Another reason this may occur is if a package you are trying to emerge requiresan older version of a package in order to emerge successfully. In this case,libgd 2.x is incompatible with libgd 1.x. This means that packages that werecreated with libgd 1.x will not compile with 2.x and must downgrade libgd firstbefore they can emerge.
[ebuild U ] sys-devel/distcc-2.16 [2.13-r1] USE=ipv6* -gtk -qt%: Here we see that the make.conf variable USE affects how this package isbuilt. In this example, ipv6 optional support is enabled and both gtk and qtsupport are disabled. The asterisk following ipv6 indicates that ipv6 supportwas disabled the last time this package was installed. The percent signfollowing qt indicates that the qt option has been added to the package sinceit was last installed. For information about all USE symbols, see the--verbose option documentation above.
*Note: Flags that haven't changed since the last install are onlydisplayed when you use the --pretend and --verbose options.Using the --quiet option will prevent all information from beingdisplayed.
[ebuild r U ] dev-libs/icu-50.1.1:0/50.1.1 [50.1-r2:0/50.1]: Icu 50.1-r2 has already been emerged and can be Updated to version50.1.1. The r symbol indicates that a sub-slot change (from 50.1to 50.1.1 in this case) will force packages having slot-operatordependencies on it to be rebuilt (as libxml2 will be rebuilt in the nextexample).
[ebuild rR ] dev-libs/libxml2-2.9.0-r1:2 USE=icu: Libxml2 2.9.0-r1 has already been emerged, but if you run the command,then portage will Re-emerge it in order to satisfy a slot-operatordependency which forces it to be rebuilt when the icu sub-slot changes(as it changed in the previous example).
[ebuild U *] sys-apps/portage-2.2.0_alpha6 [2.1.9.25]

Symbol	Mask Type
#	package.mask
*	missing keyword
~	unstable keyword