Section: Portage (1)
Updated: Dec 2015


egencache - generate metadata cache for ebuild repositories  


egencache [options] --update [ATOM]...  


The egencache program generates metadata cache for ebuild repositories and stores it in the metadata/md5-cache/ directory within the repository itself, for distribution.  


--update [ATOM] ...
Update the metadata/md5-cache/ directory (generate metadata as necessary). If no package atoms are specified then all will be updated. See ebuild(5) for the details on package atom syntax.
Update the ChangeLog files from SCM logs (supported only in git repos).
Update the package description index which is located at metadata/pkg_desc_index in the repository.
Update the profiles/use.local.desc file from metadata.xml.
Update manifest files, and sign them if signing is enabled. This supports parallelization if enabled via the --jobs option. The --thin-manifests and --sign-manifests options may be used to manually override layout.conf settings.


Location of the intermediate metadata cache which is stored in a different format that includes eclass state. See the BUGS section for information about why this is necessary.
Defaults to /var/cache/edb/dep.
Specifies the file name used to store autogenerated ChangeLogs inside the package directories.
Defaults to ChangeLog.
Reverses the commit order in ChangeLogs. The oldest commits are output first, the newest last.
Location of portage config files.
Defaults to /.
Override the PORTAGE_GPG_DIR variable.
Override the PORTAGE_GPG_KEY variable.
Causes EGENCACHE_DEFAULT_OPTS to be ignored.
Specifies the maximum number of ebuild processes to spawn simultaneously. Also see the related --load-average option.
Specifies that maximum load allowed when spawning multiple jobs.
Preserve the comments found in the output use.local.desc file. This requires the output file to exist before egencache is called.
Name of the repo to operate on. The name should correspond the value of a repo_name entry (see portage(5)) from one of the repositories.
Override configuration of repositories. The argument of this option has the same format as repos.conf (see portage(5)).
When used together with the --update action, this enables a workaround for cases in which the content of a cache entry changes and neither the file mtime nor size changes, preventing rsync from detecting changes. Such cases are handled by bumping the mtime on the ebuild (and the corresponding cache entry). This option should only be needed for distribution via something like rsync(1), which relies on timestamps and file sizes to detect changes (see bug 139134). It's not needed with git(1) since that uses a more thorough mechanism which allows it to detect changed inode numbers (described in racy-git.txt in the git technical docs).
--sign-manifests< y | n >
Manually override layout.conf sign-manifests setting.
--strict-manifests< y | n >
Manually override "strict" FEATURES setting.
--thin-manifests< y | n >
Manually override layout.conf thin-manifests setting.
Exit successfully if only minor errors occurred, such as skipped cache updates due to ebuilds that either fail to source or are not sourced due to invalid Manifest entries.
Output file for use.local.desc data (or '-' for stdout)
Write metadata/timestamp.chk as required for rsync repositories


If this variable is set in make.conf(5) then any options that it contains will be added to the beginning of the command line on every invocation. These options will not be added if the --ignore-default-opts option is specified.


Prior to portage-, the 'pms' cache format was enabled by default. This 'pms' format, which is distributed in the metadata/cache/ directory of the repository, has significant limitations related to the cache validation mechanism which involves comparison of a cache entry mtime to the mtime of the corresponding ebuild(5). This mechanism is unreliable in cases when eclass changes result in metadata changes, since no information about eclass state is available in the cache. Also, since the mtime of the cache entry must correspond to that of the ebuild, the cache format is only suitable for distribution via protocols that preserve timestamps (such as rsync(1)). For cache that is distributed via git(1) repositories, there is currently a workaround implemented in emerge(1) --sync which updates ebuild mtimes to match their corresponding cache entries (except for ebuilds that are modified relative to HEAD).

In order to solve the above problems, the newer 'md5-dict' format has been enabled by default since portage- This format is distributed in the metadata/md5-cache/ directory of the repository, and includes additional validation data in the form of digests for both the ebuild and its inherited eclasses. WARNING: Portage versions prior to portage- will NOT recognize the 'md5-dict' format unless it is explicitly listed in metadata/layout.conf (refer to portage(5) for example usage).

WARNING: For backward compatibility, the obsolete 'pms' cache format will still be generated by default if the metadata/cache/ directory exists in the repository. It can also be explicitly enabled via the cache-formats setting in metadata/layout.conf (refer to portage(5) for example usage). If the 'pms' cache format is enabled and the 'md5-dict' format is not enabled, then it is necessary to enable metadata-transfer in FEATURES (see make.conf(5)). This causes intermediate cache (in a different format that includes eclass state) to be generated inside the directory which is configurable via the --cache-dir option.  


Please report bugs via  


Zac Medico <>
Arfrever Frehtes Taifersar Arahesis <>


Contains variables.


emerge(1), make.conf(5), portage(5)




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Time: 16:46:11 GMT, August 14, 2017