NAME
git-fetch - Download objects and refs from another repositorySYNOPSIS
git fetch [<options>] [<repository> [<refspec>...]] git fetch [<options>] <group> git fetch --multiple [<options>] [(<repository> | <group>)...] git fetch --all [<options>]
DESCRIPTION
Fetch branches and/or tags (collectively, "refs") from one or more other repositories, along with the objects necessary to complete their histories. Remote-tracking branches are updated (see the description of <refspec> below for ways to control this behavior).OPTIONS
--allFetch all remotes.
-a, --append
Append ref names and object names of fetched
refs to the existing contents of .git/FETCH_HEAD. Without this option
old data in .git/FETCH_HEAD will be overwritten.
--atomic
Use an atomic transaction to update local
refs. Either all refs are updated, or on error, no refs are updated.
--depth=<depth>
Limit fetching to the specified number of
commits from the tip of each remote branch history. If fetching to a
shallow repository created by git clone with
--depth=<depth> option (see git-clone(1)), deepen or
shorten the history to the specified number of commits. Tags for the deepened
commits are not fetched.
--deepen=<depth>
Similar to --depth, except it specifies the
number of commits from the current shallow boundary instead of from the tip of
each remote branch history.
--shallow-since=<date>
Deepen or shorten the history of a shallow
repository to include all reachable commits after <date>.
--shallow-exclude=<revision>
Deepen or shorten the history of a shallow
repository to exclude commits reachable from a specified remote branch or tag.
This option can be specified multiple times.
--unshallow
If the source repository is complete, convert
a shallow repository to a complete one, removing all the limitations imposed
by shallow repositories.
If the source repository is shallow, fetch as much as possible so that the
current repository has the same history as the source repository.
--update-shallow
By default when fetching from a shallow
repository, git fetch refuses refs that require updating .git/shallow.
This option updates .git/shallow and accept such refs.
--negotiation-tip=<commit|glob>
By default, Git will report, to the server,
commits reachable from all local refs to find common commits in an attempt to
reduce the size of the to-be-received packfile. If specified, Git will only
report commits reachable from the given tips. This is useful to speed up
fetches when the user knows which local ref is likely to have commits in
common with the upstream ref being fetched.
This option may be specified more than once; if so, Git will report commits
reachable from any of the given commits.
The argument to this option may be a glob on ref names, a ref, or the (possibly
abbreviated) SHA-1 of a commit. Specifying a glob is equivalent to specifying
this option multiple times, one for each matching ref name.
See also the fetch.negotiationAlgorithm and push.negotiate
configuration variables documented in git-config(1), and the
--negotiate-only option below.
--negotiate-only
Do not fetch anything from the server, and
instead print the ancestors of the provided --negotiation-tip=*
arguments, which we have in common with the server.
This is incompatible with --recurse-submodules=[yes|on-demand].
Internally this is used to implement the push.negotiate option, see
git-config(1).
--dry-run
Show what would be done, without making any
changes.
--[no-]write-fetch-head
Write the list of remote refs fetched in the
FETCH_HEAD file directly under $GIT_DIR. This is the default.
Passing --no-write-fetch-head from the command line tells Git not to
write the file. Under --dry-run option, the file is never
written.
-f, --force
When git fetch is used with
<src>:<dst> refspec it may refuse to update the local
branch as discussed in the <refspec> part below. This option
overrides that check.
-k, --keep
Keep downloaded pack.
--multiple
Allow several <repository> and
<group> arguments to be specified. No <refspec>s may be
specified.
--[no-]auto-maintenance, --[no-]auto-gc
Run git maintenance run --auto at the
end to perform automatic repository maintenance if needed. (
--[no-]auto-gc is a synonym.) This is enabled by default.
--[no-]write-commit-graph
Write a commit-graph after fetching. This
overrides the config setting fetch.writeCommitGraph.
--prefetch
Modify the configured refspec to place all
refs into the refs/prefetch/ namespace. See the prefetch task in
git-maintenance(1).
-p, --prune
Before fetching, remove any remote-tracking
references that no longer exist on the remote. Tags are not subject to pruning
if they are fetched only because of the default tag auto-following or due to a
--tags option. However, if tags are fetched due to an explicit refspec (either
on the command line or in the remote configuration, for example if the remote
was cloned with the --mirror option), then they are also subject to pruning.
Supplying --prune-tags is a shorthand for providing the tag refspec.
See the PRUNING section below for more details.
-P, --prune-tags
Before fetching, remove any local tags that no
longer exist on the remote if --prune is enabled. This option should be
used more carefully, unlike --prune it will remove any local references
(local tags) that have been created. This option is a shorthand for providing
the explicit tag refspec along with --prune, see the discussion about
that in its documentation.
See the PRUNING section below for more details.
-n, --no-tags
By default, tags that point at objects that
are downloaded from the remote repository are fetched and stored locally. This
option disables this automatic tag following. The default behavior for a
remote may be specified with the remote.<name>.tagOpt setting. See
git-config(1).
--refetch
Instead of negotiating with the server to
avoid transferring commits and associated objects that are already present
locally, this option fetches all objects as a fresh clone would. Use this to
reapply a partial clone filter from configuration or using --filter=
when the filter definition has changed. Automatic post-fetch maintenance will
perform object database pack consolidation to remove any duplicate
objects.
--refmap=<refspec>
When fetching refs listed on the command line,
use the specified refspec (can be given more than once) to map the refs to
remote-tracking branches, instead of the values of remote.*.fetch
configuration variables for the remote repository. Providing an empty
<refspec> to the --refmap option causes Git to ignore the
configured refspecs and rely entirely on the refspecs supplied as command-line
arguments. See section on "Configured Remote-tracking Branches" for
details.
-t, --tags
Fetch all tags from the remote (i.e., fetch
remote tags refs/tags/* into local tags with the same name), in
addition to whatever else would otherwise be fetched. Using this option alone
does not subject tags to pruning, even if --prune is used (though tags may be
pruned anyway if they are also the destination of an explicit refspec; see
--prune).
--recurse-submodules[=yes|on-demand|no]
This option controls if and under what
conditions new commits of submodules should be fetched too. When recursing
through submodules, git fetch always attempts to fetch
"changed" submodules, that is, a submodule that has commits that are
referenced by a newly fetched superproject commit but are missing in the local
submodule clone. A changed submodule can be fetched as long as it is present
locally e.g. in $GIT_DIR/modules/ (see gitsubmodules(7)); if the
upstream adds a new submodule, that submodule cannot be fetched until it is
cloned e.g. by git submodule update.
When set to on-demand, only changed submodules are fetched. When set to
yes, all populated submodules are fetched and submodules that are both
unpopulated and changed are fetched. When set to no, submodules are
never fetched.
When unspecified, this uses the value of fetch.recurseSubmodules if it is
set (see git-config(1)), defaulting to on-demand if unset. When
this option is used without any value, it defaults to yes.
-j, --jobs=<n>
Number of parallel children to be used for all
forms of fetching.
If the --multiple option was specified, the different remotes will be
fetched in parallel. If multiple submodules are fetched, they will be fetched
in parallel. To control them independently, use the config settings
fetch.parallel and submodule.fetchJobs (see
git-config(1)).
Typically, parallel recursive and multi-remote fetches will be faster. By
default fetches are performed sequentially, not in parallel.
--no-recurse-submodules
Disable recursive fetching of submodules (this
has the same effect as using the --recurse-submodules=no option).
--set-upstream
If the remote is fetched successfully, add
upstream (tracking) reference, used by argument-less git-pull(1) and
other commands. For more information, see branch.<name>.merge and
branch.<name>.remote in git-config(1).
--submodule-prefix=<path>
Prepend <path> to paths printed in
informative messages such as "Fetching submodule foo". This option
is used internally when recursing over submodules.
--recurse-submodules-default=[yes|on-demand]
This option is used internally to temporarily
provide a non-negative default value for the --recurse-submodules option. All
other methods of configuring fetch’s submodule recursion (such as
settings in gitmodules(5) and git-config(1)) override this
option, as does specifying --[no-]recurse-submodules directly.
-u, --update-head-ok
By default git fetch refuses to update
the head which corresponds to the current branch. This flag disables the
check. This is purely for the internal use for git pull to communicate
with git fetch, and unless you are implementing your own Porcelain you
are not supposed to use it.
--upload-pack <upload-pack>
When given, and the repository to fetch from
is handled by git fetch-pack, --exec=<upload-pack> is
passed to the command to specify non-default path for the command run on the
other end.
-q, --quiet
Pass --quiet to git-fetch-pack and silence any
other internally used git commands. Progress is not reported to the standard
error stream.
-v, --verbose
Be verbose.
--progress
Progress status is reported on the standard
error stream by default when it is attached to a terminal, unless -q is
specified. This flag forces progress status even if the standard error stream
is not directed to a terminal.
-o <option>, --server-option=<option>
Transmit the given string to the server when
communicating using protocol version 2. The given string must not contain a
NUL or LF character. The server’s handling of server options, including
unknown ones, is server-specific. When multiple
--server-option=<option> are given, they are all sent to the
other side in the order listed on the command line.
--show-forced-updates
By default, git checks if a branch is
force-updated during fetch. This can be disabled through
fetch.showForcedUpdates, but the --show-forced-updates option guarantees this
check occurs. See git-config(1).
--no-show-forced-updates
By default, git checks if a branch is
force-updated during fetch. Pass --no-show-forced-updates or set
fetch.showForcedUpdates to false to skip this check for performance reasons.
If used during git-pull the --ff-only option will still check for
forced updates before attempting a fast-forward update. See
git-config(1).
-4, --ipv4
Use IPv4 addresses only, ignoring IPv6
addresses.
-6, --ipv6
Use IPv6 addresses only, ignoring IPv4
addresses.
<repository>
The "remote" repository that is the
source of a fetch or pull operation. This parameter can be either a URL (see
the section GIT URLS below) or the name of a remote (see the section REMOTES
below).
<group>
A name referring to a list of repositories as
the value of remotes.<group> in the configuration file. (See
git-config(1)).
<refspec>
Specifies which refs to fetch and which local
refs to update. When no <refspec>s appear on the command line, the refs
to fetch are read from remote.<repository>.fetch variables
instead (see CONFIGURED REMOTE-TRACKING BRANCHES below).
The format of a <refspec> parameter is an optional plus +, followed
by the source <src>, followed by a colon :, followed by the
destination ref <dst>. The colon can be omitted when <dst> is
empty. <src> is typically a ref, but it can also be a fully spelled hex
object name.
A <refspec> may contain a * in its <src> to indicate a simple
pattern match. Such a refspec functions like a glob that matches any ref with
the same prefix. A pattern <refspec> must have a * in both the
<src> and <dst>. It will map refs to the destination by replacing
the * with the contents matched from the source.
If a refspec is prefixed by ^, it will be interpreted as a negative
refspec. Rather than specifying which refs to fetch or which local refs to
update, such a refspec will instead specify refs to exclude. A ref will be
considered to match if it matches at least one positive refspec, and does not
match any negative refspec. Negative refspecs can be useful to restrict the
scope of a pattern refspec so that it will not include specific refs. Negative
refspecs can themselves be pattern refspecs. However, they may only contain a
<src> and do not specify a <dst>. Fully spelled out hex object
names are also not supported.
tag <tag> means the same as
refs/tags/<tag>:refs/tags/<tag>; it requests fetching
everything up to the given tag.
The remote ref that matches <src> is fetched, and if <dst> is not an
empty string, an attempt is made to update the local ref that matches it.
Whether that update is allowed without --force depends on the ref
namespace it’s being fetched to, the type of object being fetched, and
whether the update is considered to be a fast-forward. Generally, the same
rules apply for fetching as when pushing, see the <refspec>...
section of git-push(1) for what those are. Exceptions to those rules
particular to git fetch are noted below.
Until Git version 2.20, and unlike when pushing with git-push(1), any
updates to refs/tags/* would be accepted without + in the
refspec (or --force). When fetching, we promiscuously considered all
tag updates from a remote to be forced fetches. Since Git version 2.20,
fetching to update refs/tags/* works the same way as when pushing. I.e.
any updates will be rejected without + in the refspec (or
--force).
Unlike when pushing with git-push(1), any updates outside of
refs/{tags,heads}/* will be accepted without + in the refspec
(or --force), whether that’s swapping e.g. a tree object for a
blob, or a commit for another commit that’s doesn’t have the
previous commit as an ancestor etc.
Unlike when pushing with git-push(1), there is no configuration
which’ll amend these rules, and nothing like a pre-fetch hook
analogous to the pre-receive hook.
As with pushing with git-push(1), all of the rules described above about
what’s not allowed as an update can be overridden by adding an the
optional leading + to a refspec (or using --force command line
option). The only exception to this is that no amount of forcing will make the
refs/heads/* namespace accept a non-commit object.
Note
When the remote branch you want to fetch is known to be rewound and rebased
regularly, it is expected that its new tip will not be descendant of its
previous tip (as stored in your remote-tracking branch the last time you
fetched). You would want to use the + sign to indicate non-fast-forward
updates will be needed for such branches. There is no way to determine or
declare that a branch will be made available in a repository with this
behavior; the pulling user simply must know this is the expected usage pattern
for a branch.
--stdin
Read refspecs, one per line, from stdin in
addition to those provided as arguments. The "tag <name>"
format is not supported.
GIT URLS
In general, URLs contain information about the transport protocol, the address of the remote server, and the path to the repository. Depending on the transport protocol, some of this information may be absent.•ssh://[user@]host.xz[:port]/path/to/repo.git/
•git://host.xz[:port]/path/to/repo.git/
•http[s]://host.xz[:port]/path/to/repo.git/
•ftp[s]://host.xz[:port]/path/to/repo.git/
•[user@]host.xz:path/to/repo.git/
•ssh://[user@]host.xz[:port]/~[user]/path/to/repo.git/
•git://host.xz[:port]/~[user]/path/to/repo.git/
•[user@]host.xz:/~[user]/path/to/repo.git/
•/path/to/repo.git/
•file:///path/to/repo.git/
•<transport>::<address>
[url "<actual url base>"] insteadOf = <other url base>
[url "git://git.host.xz/"] insteadOf = host.xz:/path/to/ insteadOf = work:
[url "<actual url base>"] pushInsteadOf = <other url base>
[url "ssh://example.org/"] pushInsteadOf = git://example.org/
REMOTES
The name of one of the following can be used instead of a URL as <repository> argument:•a remote in the Git configuration
file: $GIT_DIR/config,
•a file in the $GIT_DIR/remotes
directory, or
•a file in the $GIT_DIR/branches
directory.
Named remote in configuration file
You can choose to provide the name of a remote which you had previously configured using git-remote(1), git-config(1) or even by a manual edit to the $GIT_DIR/config file. The URL of this remote will be used to access the repository. The refspec of this remote will be used by default when you do not provide a refspec on the command line. The entry in the config file would appear like this:[remote "<name>"] url = <URL> pushurl = <pushurl> push = <refspec> fetch = <refspec>
Named file in $GIT_DIR/remotes
You can choose to provide the name of a file in $GIT_DIR/remotes. The URL in this file will be used to access the repository. The refspec in this file will be used as default when you do not provide a refspec on the command line. This file should have the following format:URL: one of the above URL format Push: <refspec> Pull: <refspec>
Named file in $GIT_DIR/branches
You can choose to provide the name of a file in $GIT_DIR/branches. The URL in this file will be used to access the repository. This file should have the following format:<URL>#<head>
refs/heads/<head>:refs/heads/<branch>
HEAD:refs/heads/<head>
CONFIGURED REMOTE-TRACKING BRANCHES
You often interact with the same remote repository by regularly and repeatedly fetching from it. In order to keep track of the progress of such a remote repository, git fetch allows you to configure remote.<repository>.fetch configuration variables.[remote "origin"] fetch = +refs/heads/*:refs/remotes/origin/*
•When git fetch is run without
specifying what branches and/or tags to fetch on the command line, e.g. git
fetch origin or git fetch, remote.<repository>.fetch
values are used as the refspecs—they specify which refs to fetch and
which local refs to update. The example above will fetch all branches that
exist in the origin (i.e. any ref that matches the left-hand side of
the value, refs/heads/*) and update the corresponding remote-tracking
branches in the refs/remotes/origin/* hierarchy.
•When git fetch is run with
explicit branches and/or tags to fetch on the command line, e.g. git fetch
origin master, the <refspec>s given on the command line determine
what are to be fetched (e.g. master in the example, which is a
short-hand for master:, which in turn means "fetch the
master branch but I do not explicitly say what remote-tracking branch
to update with it from the command line"), and the example command will
fetch only the master branch. The
remote.<repository>.fetch values determine which remote-tracking
branch, if any, is updated. When used in this way, the
remote.<repository>.fetch values do not have any effect in
deciding what gets fetched (i.e. the values are not used as refspecs
when the command-line lists refspecs); they are only used to decide
where the refs that are fetched are stored by acting as a
mapping.
PRUNING
Git has a default disposition of keeping data unless it’s explicitly thrown away; this extends to holding onto local references to branches on remotes that have themselves deleted those branches.# While fetching $ git fetch --prune <name> # Only prune, don't fetch $ git remote prune <name>
# These both fetch tags $ git fetch --no-tags origin 'refs/tags/*:refs/tags/*' $ git fetch --no-tags --prune-tags origin
$ git fetch origin --prune --prune-tags $ git fetch origin --prune 'refs/tags/*:refs/tags/*' $ git fetch <url of origin> --prune --prune-tags $ git fetch <url of origin> --prune 'refs/tags/*:refs/tags/*'
OUTPUT
The output of "git fetch" depends on the transport method used; this section describes the output when fetching over the Git protocol (either locally or via ssh) and Smart HTTP protocol.<flag> <summary> <from> -> <to> [<reason>]
A single character indicating the status of
the ref:
(space)
summary
for a successfully fetched fast-forward;
+
for a successful forced update;
-
for a successfully pruned ref;
t
for a successful tag update;
*
for a successfully fetched new ref;
!
for a ref that was rejected or failed to
update; and
=
for a ref that was up to date and did not need
fetching.
For a successfully fetched ref, the summary
shows the old and new values of the ref in a form suitable for using as an
argument to git log (this is <old>..<new> in most
cases, and <old>...<new> for forced non-fast-forward
updates).
from
The name of the remote ref being fetched from,
minus its refs/<type>/ prefix. In the case of deletion, the name
of the remote ref is "(none)".
to
The name of the local ref being updated, minus
its refs/<type>/ prefix.
reason
A human-readable explanation. In the case of
successfully fetched refs, no explanation is needed. For a failed ref, the
reason for failure is described.
EXAMPLES
•Update the remote-tracking branches:
The above command copies all branches from the remote refs/heads/ namespace and
stores them to the local refs/remotes/origin/ namespace, unless the
branch.<name>.fetch option is used to specify a non-default
refspec.
$ git fetch origin
•Using refspecs explicitly:
This updates (or creates, as necessary) branches seen and tmp in
the local repository by fetching from the branches (respectively) seen
and maint from the remote repository.
The seen branch will be updated even if it does not fast-forward, because
it is prefixed with a plus sign; tmp will not be.
$ git fetch origin +seen:seen maint:tmp
•Peek at a remote’s branch,
without configuring the remote in your local repository:
The first command fetches the maint branch from the repository at
git://git.kernel.org/pub/scm/git/git.git and the second command uses
FETCH_HEAD to examine the branch with git-log(1). The fetched
objects will eventually be removed by git’s built-in housekeeping (see
git-gc(1)).
$ git fetch git://git.kernel.org/pub/scm/git/git.git maint $ git log FETCH_HEAD
SECURITY
The fetch and push protocols are not designed to prevent one side from stealing data from the other repository that was not intended to be shared. If you have private data that you need to protect from a malicious peer, your best option is to store it in another repository. This applies to both clients and servers. In particular, namespaces on a server are not effective for read access control; you should only grant read access to a namespace to clients that you would trust with read access to the entire repository. 1.The victim sends "have" lines
advertising the IDs of objects it has that are not explicitly intended to be
shared but can be used to optimize the transfer if the peer also has them. The
attacker chooses an object ID X to steal and sends a ref to X, but
isn’t required to send the content of X because the victim already has
it. Now the victim believes that the attacker has X, and it sends the content
of X back to the attacker later. (This attack is most straightforward for a
client to perform on a server, by creating a ref to X in the namespace the
client has access to and then fetching it. The most likely way for a server to
perform it on a client is to "merge" X into a public branch and hope
that the user does additional work on this branch and pushes it back to the
server without noticing the merge.)
2.As in #1, the attacker chooses an object ID
X to steal. The victim sends an object Y that the attacker already has, and
the attacker falsely claims to have X and not Y, so the victim sends Y as a
delta against X. The delta reveals regions of X that are similar to Y to the
attacker.
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: fetch.recurseSubmodulesThis option controls whether git fetch
(and the underlying fetch in git pull) will recursively fetch into
populated submodules. This option can be set either to a boolean value or to
on-demand. Setting it to a boolean changes the behavior of fetch and
pull to recurse unconditionally into submodules when set to true or to not
recurse at all when set to false. When set to on-demand, fetch and pull
will only recurse into a populated submodule when its superproject retrieves a
commit that updates the submodule’s reference. Defaults to
on-demand, or to the value of submodule.recurse if set.
fetch.fsckObjects
If it is set to true, git-fetch-pack will
check all fetched objects. See transfer.fsckObjects for what’s
checked. Defaults to false. If not set, the value of
transfer.fsckObjects is used instead.
fetch.fsck.<msg-id>
Acts like fsck.<msg-id>, but is
used by git-fetch-pack(1) instead of git-fsck(1). See the
fsck.<msg-id> documentation for details.
fetch.fsck.skipList
Acts like fsck.skipList, but is used by
git-fetch-pack(1) instead of git-fsck(1). See the
fsck.skipList documentation for details.
fetch.unpackLimit
If the number of objects fetched over the Git
native transfer is below this limit, then the objects will be unpacked into
loose object files. However if the number of received objects equals or
exceeds this limit then the received pack will be stored as a pack, after
adding any missing delta bases. Storing the pack from a push can make the push
operation complete faster, especially on slow filesystems. If not set, the
value of transfer.unpackLimit is used instead.
fetch.prune
If true, fetch will automatically behave as if
the --prune option was given on the command line. See also
remote.<name>.prune and the PRUNING section of
.
fetch.pruneTags
If true, fetch will automatically behave as if
the refs/tags/*:refs/tags/* refspec was provided when pruning, if not
set already. This allows for setting both this option and fetch.prune
to maintain a 1=1 mapping to upstream refs. See also
remote.<name>.pruneTags and the PRUNING section of
.
fetch.output
Control how ref update status is printed.
Valid values are full and compact. Default value is full.
See section OUTPUT in for detail.
fetch.negotiationAlgorithm
Control how information about the commits in
the local repository is sent when negotiating the contents of the packfile to
be sent by the server. Set to "consecutive" to use an algorithm that
walks over consecutive commits checking each one. Set to "skipping"
to use an algorithm that skips commits in an effort to converge faster, but
may result in a larger-than-necessary packfile; or set to "noop" to
not send any information at all, which will almost certainly result in a
larger-than-necessary packfile, but will skip the negotiation step. Set to
"default" to override settings made previously and use the default
behaviour. The default is normally "consecutive", but if
feature.experimental is true, then the default is "skipping".
Unknown values will cause git fetch to error out.
See also the --negotiate-only and --negotiation-tip options to
.
fetch.showForcedUpdates
Set to false to enable
--no-show-forced-updates in and git-pull(1)
commands. Defaults to true.
fetch.parallel
Specifies the maximal number of fetch
operations to be run in parallel at a time (submodules, or remotes when the
--multiple option of is in effect).
A value of 0 will give some reasonable default. If unset, it defaults to 1.
For submodules, this setting can be overridden using the
submodule.fetchJobs config setting.
fetch.writeCommitGraph
Set to true to write a commit-graph after
every git fetch command that downloads a pack-file from a remote. Using
the --split option, most executions will create a very small
commit-graph file on top of the existing commit-graph file(s). Occasionally,
these files will merge and the write may take longer. Having an updated
commit-graph file helps performance of many Git commands, including git
merge-base, git push -f, and git log --graph. Defaults to
false.
BUGS
Using --recurse-submodules can only fetch new commits in submodules that are present locally e.g. in $GIT_DIR/modules/. If the upstream adds a new submodule, that submodule cannot be fetched until it is cloned e.g. by git submodule update. This is expected to be fixed in a future Git version.SEE ALSO
git-pull(1)GIT
Part of the git(1) suite02/28/2023 | Git 2.39.2 |