emerge

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emerge is the command-line interface to Portage and is how most users will interact with Portage. It is one of the most important commands on Gentoo.

emerge is used to install, update, and generally maintain software packages on Gentoo Linux.

Tip
The emerge command has many possible options. For extensive documentation and a complete list of all options see man emerge.

Note
Some common questions about the emerge command are answered in the FAQ and the Portage FAQ. See also the Portage article.

Usage

Invocation

Running emerge with the --help option provides information on command line options:

user $emerge --help

emerge: command-line interface to the Portage system
Usage:
   emerge [ options ] [ action ] [ ebuild | tbz2 | file | @set | atom ] [ ... ]
   emerge [ options ] [ action ] < @system | @world >
   emerge < --sync | --metadata | --info >
   emerge --resume [ --pretend | --ask | --skipfirst ]
   emerge --help
Options: -[abBcCdDefgGhjkKlnNoOpPqrsStuUvVwW]
          [ --color < y | n >            ] [ --columns    ]
          [ --complete-graph             ] [ --deep       ]
          [ --jobs JOBS ] [ --keep-going ] [ --load-average LOAD            ]
          [ --newrepo   ] [ --newuse     ] [ --noconfmem  ] [ --nospinner   ]
          [ --oneshot   ] [ --onlydeps   ] [ --quiet-build [ y | n ]        ]
          [ --reinstall changed-use      ] [ --with-bdeps < y | n >         ]
Actions:  [ --depclean | --list-sets | --search | --sync | --version        ]

   For more help consult the man page.

Below is an example invocation of emerge, installing "package". The options (-atv) are short options for --ask, --tree, and --verbose. They trigger emerge to ask before proceeding, display the dependency tree of packages to be installed, and to be verbose with its output:

# emerge -atv package
These are the packages that would be merged, in reverse order:
Calculating dependencies... done!
[ebuild     U  ] category/package-3.0-r2 [2.0] USE="enabled -disabled toggled* new% (-unavailable)" MAKE_OPTIONS="-disabled" 777 kB
[ebuild     UD ]  category/package-2.0 [3.0] 777 kB
[ebuild   R    ]   category/package-1.0  777 kB
[ebuild  N     ]  category/package-0.5  777 kB
Total: 4 packages (1 new, 1 reinstall, 1 upgrade, 1 downgrade), Size of downloads: 3108 kB
Would you like to merge these packages? [Yes/No]

The U symbol shows a package that will be upgraded, D a package that will be downgraded, R re-emerged, N a new package. In square brackets is the version of the previously installed package. See the OUTPUT section of the emerge man page for complete explanation.

In the context of Portage, the term "package" can also be referred to as an "atom", the terms can be used interchangeably. See version specifier.

Install a package

Install the net-proxy/tinyproxy package with --ask and --verbose options for precaution:

root #emerge --ask --verbose net-proxy/tinyproxy

Tip
The --ask (-a) option is very useful, it will allow the emerge actions to be reviewed before the actual operation begins. The --verbose (-v) option will show more detailed information about what Portage will do, and is often helpful.

Warning
If the --ask option is not provided, requested actions will be performed without ever asking for confirmation. The --pretend option may also be used.

Options can be set as default, if desired. Default options can be overridden on the command line, for example --ask=n.

Search for packages

Note
The built-in search of emerge may show limited results compared to other tools. The Latest version available is constrained by the ACCEPT_KEYWORDS in make.conf (or the environment). In addition, Latest version available and Latest installed version are not slot aware so will not show multiple versions by slot. This can lead to some confusion which tools like eix or eshowkw might show more versions.

Search for packages with proxy in their names:

user $emerge --search proxy

Search for packages with proxy in their names or description:

user $emerge --searchdesc proxy

Search packages using a regular expression:

user $emerge -s '%^python$'

List all packages in a category:

user $emerge -s '@net-ftp'

The repository can also be searched online at packages.gentoo.org.

Remove (uninstall) packages

Remove the net-proxy/tinyproxy package using the dependency sensitive --depclean option:

root #emerge --ask --verbose --depclean net-proxy/tinyproxy

This should only remove packages that are not needed as a dependency of a currently installed package.

Warning
Do not use the --unmerge option (unless its particular behavior is known to be specifically required). This option will remove important packages that are needed for the system to function, without warning. To uninstall a package, use the --depclean option.

Cleaning out orphaned packages

See also
See remove orphaned packages for information on how to use emerge --depclean to remove potentially unused packages. See also the Portage FAQ.

Update packages

See Upgrading Gentoo for how to update packages.

Tips

Verifying and (re)downloading distfiles

To re-verify the integrity of and re-download previously removed/corrupted distfiles for all currently installed packages, run:

root #emerge --ask --fetchonly --emptytree @world

Do not add dependencies to the world file

If a dependency must be reinstalled, use the --oneshot option. Installing dependencies with the emerge package command would add them to the world file and may lead to issues.

Installing dependencies with Portage for compiling custom source software is also ill advised: it is preferable to write an ebuild.

Resume emerge

If an emerge of several packages is interrupted (e.g. ctrl+c, crash...), the emerge may be resumed from the failed package with the --resume option. The --keep-going and --skip-first options may also be of interest. See the emerge man page for details.

Troubleshooting

See also
See User:Sam/Portage_help for topics on Portage issues.

Emerging packages fail during 'unpack' stage

The following message can occur when emerging packages:

 * Error messages for package dev-libs/libinput-1.16.0:
 * The ebuild phase 'unpack' has exited unexpectedly. This type of behavior
 * is known to be triggered by things such as failed variable assignments
 * (bug #190128) or bad substitution errors (bug #200313). Normally, before
 * exiting, bash should have displayed an error message above. If bash did
 * not produce an error message above, it's possible that the ebuild has
 * called `exit` when it should have called `die` instead. This behavior
 * may also be triggered by a corrupt bash binary or a hardware problem
 * such as memory or cpu malfunction. If the problem is not reproducible or
 * it appears to occur randomly, then it is likely to be triggered by a
 * hardware problem. If you suspect a hardware problem then you should try
 * some basic hardware diagnostics such as memtest. Please do not report
 * this as a bug unless it is consistently reproducible and you are sure
 * that your bash binary and hardware are functioning properly.

Although this issue may be due the reasons listed in the output above, it can often be caused by low disk space in the path used by Portage to unpack the ebuild's source files. This location is set via the PORTAGE_TMPDIR variable and can be quickly found by querying Portage:

user $portageq envvar PORTAGE_TMPDIR

/var/tmp

The df command may be used to view available disk space for the partition where PORTAGE_TMPDIR has been mounted (this will likely be the root (/) partition). See Freeing disk space for details on how to free up disk space.