git-fsck

GIT-FSCK(1)                        Git Manual                        GIT-FSCK(1)



NAME
       git-fsck - Verifies the connectivity and validity of the objects in the
       database

SYNOPSIS
       git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
                [--[no-]full] [--strict] [--verbose] [--lost-found]
                [--[no-]dangling] [--[no-]progress] [--connectivity-only]
                [--[no-]name-objects] [<object>*]


DESCRIPTION
       Verifies the connectivity and validity of the objects in the database.

OPTIONS
       <object>
           An object to treat as the head of an unreachability trace.

           If no objects are given, git fsck defaults to using the index file,
           all SHA-1 references in refs namespace, and all reflogs (unless
           --no-reflogs is given) as heads.

       --unreachable
           Print out objects that exist but that aren’t reachable from any of
           the reference nodes.

       --[no-]dangling
           Print objects that exist but that are never directly used (default).
           --no-dangling can be used to omit this information from the output.

       --root
           Report root nodes.

       --tags
           Report tags.

       --cache
           Consider any object recorded in the index also as a head node for an
           unreachability trace.

       --no-reflogs
           Do not consider commits that are referenced only by an entry in a
           reflog to be reachable. This option is meant only to search for
           commits that used to be in a ref, but now aren’t, but are still in
           that corresponding reflog.

       --full
           Check not just objects in GIT_OBJECT_DIRECTORY ($GIT_DIR/objects),
           but also the ones found in alternate object pools listed in
           GIT_ALTERNATE_OBJECT_DIRECTORIES or $GIT_DIR/objects/info/alternates,
           and in packed Git archives found in $GIT_DIR/objects/pack and
           corresponding pack subdirectories in alternate object pools. This is
           now default; you can turn it off with --no-full.

       --connectivity-only
           Check only the connectivity of reachable objects, making sure that
           any objects referenced by a reachable tag, commit, or tree is
           present. This speeds up the operation by avoiding reading blobs
           entirely (though it does still check that referenced blobs exist).
           This will detect corruption in commits and trees, but not do any
           semantic checks (e.g., for format errors). Corruption in blob objects
           will not be detected at all.

           Unreachable tags, commits, and trees will also be accessed to find
           the tips of dangling segments of history. Use --no-dangling if you
           don’t care about this output and want to speed it up further.

       --strict
           Enable more strict checking, namely to catch a file mode recorded
           with g+w bit set, which was created by older versions of Git.
           Existing repositories, including the Linux kernel, Git itself, and
           sparse repository have old objects that triggers this check, but it
           is recommended to check new projects with this flag.

       --verbose
           Be chatty.

       --lost-found
           Write dangling objects into .git/lost-found/commit/ or
           .git/lost-found/other/, depending on type. If the object is a blob,
           the contents are written into the file, rather than its object name.

       --name-objects
           When displaying names of reachable objects, in addition to the SHA-1
           also display a name that describes how they are reachable, compatible
           with git-rev-parse(1), e.g.  HEAD@{1234567890}~25^2:src/.

       --[no-]progress
           Progress status is reported on the standard error stream by default
           when it is attached to a terminal, unless --no-progress or --verbose
           is specified. --progress forces progress status even if the standard
           error stream is not directed to a terminal.

CONFIGURATION
       fsck.<msg-id>
           During fsck git may find issues with legacy data which wouldn’t be
           generated by current versions of git, and which wouldn’t be sent over
           the wire if transfer.fsckObjects was set. This feature is intended to
           support working with legacy repositories containing such data.

           Setting fsck.<msg-id> will be picked up by git-fsck(1), but to accept
           pushes of such data set receive.fsck.<msg-id> instead, or to clone or
           fetch it set fetch.fsck.<msg-id>.

           The rest of the documentation discusses fsck.*  for brevity, but the
           same applies for the corresponding receive.fsck.*  and
           fetch.<msg-id>.*. variables.

           Unlike variables like color.ui and core.editor the
           receive.fsck.<msg-id> and fetch.fsck.<msg-id> variables will not fall
           back on the fsck.<msg-id> configuration if they aren’t set. To
           uniformly configure the same fsck settings in different circumstances
           all three of them they must all set to the same values.

           When fsck.<msg-id> is set, errors can be switched to warnings and
           vice versa by configuring the fsck.<msg-id> setting where the
           <msg-id> is the fsck message ID and the value is one of error, warn
           or ignore. For convenience, fsck prefixes the error/warning with the
           message ID, e.g. "missingEmail: invalid author/committer line -
           missing email" means that setting fsck.missingEmail = ignore will
           hide that issue.

           In general, it is better to enumerate existing objects with problems
           with fsck.skipList, instead of listing the kind of breakages these
           problematic objects share to be ignored, as doing the latter will
           allow new instances of the same breakages go unnoticed.

           Setting an unknown fsck.<msg-id> value will cause fsck to die, but
           doing the same for receive.fsck.<msg-id> and fetch.fsck.<msg-id> will
           only cause git to warn.

       fsck.skipList
           The path to a list of object names (i.e. one unabbreviated SHA-1 per
           line) that are known to be broken in a non-fatal way and should be
           ignored. On versions of Git 2.20 and later comments (#), empty lines,
           and any leading and trailing whitespace is ignored. Everything but a
           SHA-1 per line will error out on older versions.

           This feature is useful when an established project should be accepted
           despite early commits containing errors that can be safely ignored
           such as invalid committer email addresses. Note: corrupt objects
           cannot be skipped with this setting.

           Like fsck.<msg-id> this variable has corresponding
           receive.fsck.skipList and fetch.fsck.skipList variants.

           Unlike variables like color.ui and core.editor the
           receive.fsck.skipList and fetch.fsck.skipList variables will not fall
           back on the fsck.skipList configuration if they aren’t set. To
           uniformly configure the same fsck settings in different circumstances
           all three of them they must all set to the same values.

           Older versions of Git (before 2.20) documented that the object names
           list should be sorted. This was never a requirement, the object names
           could appear in any order, but when reading the list we tracked
           whether the list was sorted for the purposes of an internal binary
           search implementation, which could save itself some work with an
           already sorted list. Unless you had a humongous list there was no
           reason to go out of your way to pre-sort the list. After Git version
           2.20 a hash implementation is used instead, so there’s now no reason
           to pre-sort the list.

DISCUSSION
       git-fsck tests SHA-1 and general object sanity, and it does full tracking
       of the resulting reachability and everything else. It prints out any
       corruption it finds (missing or bad objects), and if you use the
       --unreachable flag it will also print out objects that exist but that
       aren’t reachable from any of the specified head nodes (or the default
       set, as mentioned above).

       Any corrupt objects you will have to find in backups or other archives
       (i.e., you can just remove them and do an rsync with some other site in
       the hopes that somebody else has the object you have corrupted).

       If core.commitGraph is true, the commit-graph file will also be inspected
       using git commit-graph verify. See git-commit-graph(1).

EXTRACTED DIAGNOSTICS
       expect dangling commits - potential heads - due to lack of head
       information
           You haven’t specified any nodes as heads so it won’t be possible to
           differentiate between un-parented commits and root nodes.

       missing sha1 directory <dir>
           The directory holding the sha1 objects is missing.

       unreachable <type> <object>
           The <type> object <object>, isn’t actually referred to directly or
           indirectly in any of the trees or commits seen. This can mean that
           there’s another root node that you’re not specifying or that the tree
           is corrupt. If you haven’t missed a root node then you might as well
           delete unreachable nodes since they can’t be used.

       missing <type> <object>
           The <type> object <object>, is referred to but isn’t present in the
           database.

       dangling <type> <object>
           The <type> object <object>, is present in the database but never
           directly used. A dangling commit could be a root node.

       hash mismatch <object>
           The database has an object whose hash doesn’t match the object
           database value. This indicates a serious data integrity problem.

ENVIRONMENT VARIABLES
       GIT_OBJECT_DIRECTORY
           used to specify the object database root (usually $GIT_DIR/objects)

       GIT_INDEX_FILE
           used to specify the index file of the index

       GIT_ALTERNATE_OBJECT_DIRECTORIES
           used to specify additional object database roots (usually unset)

GIT
       Part of the git(1) suite



Git 2.28.0                         07/27/2020                        GIT-FSCK(1)