GIT-INDEX-PACK(1) Git Manual GIT-INDEX-PACK(1)
NAME
git-index-pack - Build pack index file for an existing packed archive
SYNOPSIS
git index-pack [-v] [-o <index-file>] [--[no-]rev-index] <pack-file>
git index-pack --stdin [--fix-thin] [--keep] [-v] [-o <index-file>]
[--[no-]rev-index] [<pack-file>]
DESCRIPTION
Reads a packed archive (.pack) from the specified file, builds a pack
index file (.idx) for it, and optionally writes a reverse-index (.rev)
for the specified pack. The packed archive, together with the pack
index, can then be placed in the objects/pack/ directory of a Git
repository.
OPTIONS
-v
Be verbose about what is going on, including progress status.
-o <index-file>
Write the generated pack index into the specified file. Without this
option the name of pack index file is constructed from the name of
packed archive file by replacing .pack with .idx (and the program
fails if the name of packed archive does not end with .pack).
--[no-]rev-index
When this flag is provided, generate a reverse index (a .rev file)
corresponding to the given pack. If --verify is given, ensure that
the existing reverse index is correct. Takes precedence over
pack.writeReverseIndex.
--stdin
When this flag is provided, the pack is read from stdin instead and
a copy is then written to <pack-file>. If <pack-file> is not
specified, the pack is written to objects/pack/ directory of the
current Git repository with a default name determined from the pack
content. If <pack-file> is not specified consider using --keep to
prevent a race condition between this process and git repack.
--fix-thin
Fix a "thin" pack produced by git pack-objects --thin (see git-pack-
objects(1) for details) by adding the excluded objects the deltified
objects are based on to the pack. This option only makes sense in
conjunction with --stdin.
--keep
Before moving the index into its final destination create an empty
.keep file for the associated pack file. This option is usually
necessary with --stdin to prevent a simultaneous git repack process
from deleting the newly constructed pack and index before refs can
be updated to use objects contained in the pack.
--keep=<msg>
Like --keep, create a .keep file before moving the index into its
final destination. However, instead of creating an empty file place
<msg> followed by an LF into the .keep file. The <msg> message can
later be searched for within all .keep files to locate any which
have outlived their usefulness.
--index-version=<version>[,<offset>]
This is intended to be used by the test suite only. It allows to
force the version for the generated pack index, and to force 64-bit
index entries on objects located above the given offset.
--strict[=<msg-id>=<severity>...]
Die, if the pack contains broken objects or links. An optional
comma-separated list of <msg-id>=<severity> can be passed to change
the severity of some possible issues, e.g.,
--strict="missingEmail=ignore,badTagName=error". See the entry for
the fsck.<msg-id> configuration options in git-fsck(1) for more
information on the possible values of <msg-id> and <severity>.
--progress-title
For internal use only.
Set the title of the progress bar. The title is "Receiving objects"
by default and "Indexing objects" when --stdin is specified.
--check-self-contained-and-connected
Die if the pack contains broken links. For internal use only.
--fsck-objects[=<msg-id>=<severity>...]
Die if the pack contains broken objects, but unlike --strict, don’t
choke on broken links. If the pack contains a tree pointing to a
.gitmodules blob that does not exist, prints the hash of that blob
(for the caller to check) after the hash that goes into the name of
the pack/idx file (see "Notes").
An optional comma-separated list of <msg-id>=<severity> can be
passed to change the severity of some possible issues, e.g.,
--fsck-objects="missingEmail=ignore,badTagName=ignore". See the
entry for the fsck.<msg-id> configuration options in git-fsck(1) for
more information on the possible values of <msg-id> and <severity>.
--threads=<n>
Specifies the number of threads to spawn when resolving deltas. This
requires that index-pack be compiled with pthreads otherwise this
option is ignored with a warning. This is meant to reduce packing
time on multiprocessor machines. The required amount of memory for
the delta search window is however multiplied by the number of
threads. Specifying 0 will cause Git to auto-detect the number of
CPU’s and use maximum 3 threads.
--max-input-size=<size>
Die, if the pack is larger than <size>.
--object-format=<hash-algorithm>
Specify the given object format (hash algorithm) for the pack. The
valid values are sha1 and (if enabled) sha256. The default is the
algorithm for the current repository (set by
extensions.objectFormat), or sha1 if no value is set or outside a
repository.
This option cannot be used with --stdin.
Note: At present, there is no interoperability between SHA-256
repositories and SHA-1 repositories.
Historically, we warned that SHA-256 repositories may later need
backward incompatible changes when we introduce such interoperability
features. Today, we only expect compatible changes. Furthermore, if such
changes prove to be necessary, it can be expected that SHA-256
repositories created with today’s Git will be usable by future versions
of Git without data loss.
--promisor[=<message>]
Before committing the pack-index, create a .promisor file for this
pack. Particularly helpful when writing a promisor pack with
--fix-thin since the name of the pack is not final until the pack
has been fully written. If a <message> is provided, then that
content will be written to the .promisor file for future reference.
See partial clone[1] for more information.
NOTES
Once the index has been created, the hash that goes into the name of the
pack/idx file is printed to stdout. If --stdin was also used then this
is prefixed by either "pack\t", or "keep\t" if a new .keep file was
successfully created. This is useful to remove a .keep file used as a
lock to prevent the race with git repack mentioned above.
GIT
Part of the git(1) suite
NOTES
1. partial clone
file:///usr/share/doc/git/html/technical/partial-clone.html
Git 2.47.3 07/30/2025 GIT-INDEX-PACK(1)
Generated by dwww version 1.16 on Tue Dec 16 04:39:05 CET 2025.