# git-fsck

## 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] [--[no-]references] [<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 the **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 are 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 trigger
               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.
    
           --[no-]references
               Control whether to check the references database consistency
               via _git refs verify_. See git-refs(1) for details. The default
               is to check the references database.
    


## CONFIGURATION



           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.fsck.***. 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 must be 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 the **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 are 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 must be 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



           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.
    


## FSCK MESSAGES



           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.
    
           **badPackedRefEntry**
               (ERROR) The "packed-refs" file contains an invalid entry.
    
           **badPackedRefHeader**
               (ERROR) The "packed-refs" file contains an invalid header.
    
           **badParentSha1**
               (ERROR) A commit object has a bad parent sha1.
    
           **badRefContent**
               (ERROR) A ref has bad content.
    
           **badRefFiletype**
               (ERROR) A ref has a bad file type.
    
           **badRefName**
               (ERROR) A ref has an invalid format.
    
           **badReferentName**
               (ERROR) The referent name of a symref is invalid.
    
           **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.
    
           **emptyPackedRefsFile**
               (INFO) "packed-refs" file is empty. Report to the
               **git@vger.kernel.org******[1] mailing list if you see this error. As
               only very early versions of Git would create such an empty
               "packed_refs" file, we might tighten this rule in the future.**extraHeaderEntry**
               (IGNORE) Extra headers found after **tagger**.
    
           **fullPathname**
               (WARN) A path contains the full path starting with "/".
    
           **gitattributesBlob**
               (ERROR) A non-blob found at **.gitattributes**.
    
           **gitattributesLarge**
               (ERROR) The **.gitattributes** blob is too large.
    
           **gitattributesLineLength**
               (ERROR) The **.gitattributes** blob contains too long lines.
    
           **gitattributesMissing**
               (ERROR) Unable to read **.gitattributes** blob.
    
           **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**.
    
           **largePathname**
               (WARN) A tree contains an entry with a very long path name. If
               the value of **fsck.largePathname** contains a colon, that value
               is used as the maximum allowable length (e.g., "warn:10" would
               complain about any path component of 11 or more bytes). The
               default value is 4096.
    
           **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 an 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.
    
           **packedRefEntryNotTerminated**
               (ERROR) The "packed-refs" file contains an entry that is not
               terminated by a newline.
    
           **packedRefUnsorted**
               (ERROR) The "packed-refs" file is not sorted.
    
           **refMissingNewline**
               (INFO) A loose ref that does not end with newline(LF). As
               valid implementations of Git never created such a loose ref
               file, it may become an error in the future. Report to the
               **git@vger.kernel.org******[1] mailing list if you see this error, as
               we need to know what tools created such a file.**symlinkRef**
               (INFO) A symbolic link is used as a symref. Report to the
               **git@vger.kernel.org******[1] mailing list if you see this error, as
               we are assessing the feasibility of dropping the support to
               drop creating symbolic links as symrefs.**symrefTargetIsNotARef**
               (INFO) The target of a symbolic reference points neither to a
               root reference nor to a reference starting with "refs/".
               Although we allow create a symref pointing to the referent
               which is outside the "ref" by using **git symbolic-ref** , we may
               tighten the rule in the future. Report to the
               **git@vger.kernel.org******[1] mailing list if you see this error, as
               we need to know what tools created such a file.**trailingRefContent**
               (INFO) A loose ref has trailing content. As valid
               implementations of Git never created such a loose ref file, it
               may become an error in the future. Report to the
               **git@vger.kernel.org******[1] mailing list if you see this error, as
               we need to know what tools created such a file.**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/committer line.
    
           **zeroPaddedFilemode**
               (WARN) Found a zero padded filemode in a tree.
    


## 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
    


## NOTES



            1. git@vger.kernel.org
               mailto:git@vger.kernel.org
    


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