git-fsck - Verifies the connectivity and validity of the objects
in the database
git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
[--[no-]full] [--strict] [--verbose] [--lost-found]
[--[no-]dangling] [--[no-]progress] [--connectivity-only]
[--[no-]name-objects] [<object>...]
Verifies the connectivity and validity of the objects in the
database.
<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.
Everything below this line in this section is selectively included
from the git-config(1) documentation. The content is the same as
what’s found there:
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.
See Fsck Messages section of git-fsck(1) for
supported values of <msg-id>.
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.
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).
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.
The following lists the types of errors git fsck detects
and what each error means, with their default severity. The severity of the
error, other than those that are marked as "(FATAL)", can be
tweaked by setting the corresponding fsck.<msg-id>
configuration variable.
badDate
(ERROR) Invalid date format in an author/committer
line.
badDateOverflow
(ERROR) Invalid date value in an author/committer
line.
badEmail
(ERROR) Invalid email format in an author/committer
line.
badFilemode
(INFO) A tree contains a bad filemode entry.
badName
(ERROR) An author/committer name is empty.
badObjectSha1
(ERROR) An object has a bad sha1.
badParentSha1
(ERROR) A commit object has a bad parent sha1.
badTagName
(INFO) A tag has an invalid format.
badTimezone
(ERROR) Found an invalid time zone in an author/committer
line.
badTree
(ERROR) A tree cannot be parsed.
badTreeSha1
(ERROR) A tree has an invalid format.
badType
(ERROR) Found an invalid object type.
duplicateEntries
(ERROR) A tree contains duplicate file entries.
emptyName
(WARN) A path contains an empty name.
extraHeaderEntry
(IGNORE) Extra headers found after tagger.
fullPathname
(WARN) A path contains the full path starting with
"/".
gitattributesSymlink
(INFO) .gitattributes is a symlink.
gitignoreSymlink
(INFO) .gitignore is a symlink.
gitmodulesBlob
(ERROR) A non-blob found at .gitmodules.
gitmodulesLarge
(ERROR) The .gitmodules file is too large to
parse.
gitmodulesMissing
(ERROR) Unable to read .gitmodules blob.
gitmodulesName
(ERROR) A submodule name is invalid.
gitmodulesParse
(INFO) Could not parse .gitmodules blob.
gitmodulesLarge; (ERROR) .gitmodules blob is too
large to parse.
gitmodulesPath
(ERROR) .gitmodules path is invalid.
gitmodulesSymlink
(ERROR) .gitmodules is a symlink.
gitmodulesUpdate
(ERROR) Found an invalid submodule update setting.
gitmodulesUrl
(ERROR) Found an invalid submodule url.
hasDot
(WARN) A tree contains an entry named ..
hasDotdot
(WARN) A tree contains an entry named ...
hasDotgit
(WARN) A tree contains an entry named .git.
mailmapSymlink
(INFO) .mailmap is a symlink.
missingAuthor
(ERROR) Author is missing.
missingCommitter
(ERROR) Committer is missing.
missingEmail
(ERROR) Email is missing in an author/committer
line.
missingNameBeforeEmail
(ERROR) Missing name before an email in an
author/committer line.
missingObject
(ERROR) Missing object line in tag object.
missingSpaceBeforeDate
(ERROR) Missing space before date in an author/committer
line.
missingSpaceBeforeEmail
(ERROR) Missing space before the email in
author/committer line.
missingTag
(ERROR) Unexpected end after type line in a tag
object.
missingTagEntry
(ERROR) Missing tag line in a tag object.
missingTaggerEntry
(INFO) Missing tagger line in a tag object.
missingTree
(ERROR) Missing tree line in a commit
object.
missingType
(ERROR) Invalid type value on the type line in a
tag object.
missingTypeEntry
(ERROR) Missing type line in a tag object.
multipleAuthors
(ERROR) Multiple author lines found in a commit.
nulInCommit
(WARN) Found a NUL byte in the commit object body.
nulInHeader
(FATAL) NUL byte exists in the object header.
nullSha1
(WARN) Tree contains entries pointing to a null
sha1.
treeNotSorted
(ERROR) A tree is not properly sorted.
unknownType
(ERROR) Found an unknown object type.
unterminatedHeader
(FATAL) Missing end-of-line in the object header.
zeroPaddedDate
(ERROR) Found a zero padded date in an author/commiter
line.
zeroPaddedFilemode
(WARN) Found a zero padded filemode in a tree.
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)