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NAME

       git-fetch - Download objects and refs from another repository

SYNOPSIS

       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).

       By default, any tag that points into the histories being fetched is also fetched; the
       effect is to fetch tags that point at branches that you are interested in. This default
       behavior can be changed by using the --tags or --no-tags options or by configuring
       remote.<name>.tagOpt. By using a refspec that fetches tags explicitly, you can fetch tags
       that do not point into branches you are interested in as well.

       git fetch can fetch from either a single named repository or URL, or from several
       repositories at once if <group> is given and there is a remotes.<group> entry in the
       configuration file. (See git-config(1)).

       When no remote is specified, by default the origin remote will be used, unless there’s an
       upstream branch configured for the current branch.

       The names of refs that are fetched, together with the object names they point at, are
       written to .git/FETCH_HEAD. This information may be used by scripts or other git commands,
       such as git-pull(1).

OPTIONS

       --all
           Fetch 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.

       --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 configuration variable documented in git-
           config(1).

       --dry-run
           Show what would be done, without making any changes.

       -f, --force
           When git fetch is used with <rbranch>:<lbranch> refspec, it refuses to update the
           local branch <lbranch> unless the remote branch <rbranch> it fetches is a descendant
           of <lbranch>. 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.

       -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).

       --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. 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 populated submodules
           should be fetched too. It can be used as a boolean option to completely disable
           recursion when set to no or to unconditionally recurse into all populated submodules
           when set to yes, which is the default when this option is used without any value. Use
           on-demand to only recurse into a populated submodule when the superproject retrieves a
           commit that updates the submodule’s reference to a commit that isn’t already in the
           local submodule clone.

       -j, --jobs=<n>
           Number of parallel children to be used for fetching submodules. Each will fetch from
           different submodules, such that fetching many submodules will be faster. By default
           submodules will be fetched one at a time.

       --no-recurse-submodules
           Disable recursive fetching of submodules (this has the same effect as using the
           --recurse-submodules=no option).

       --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. When multiple
           --server-option=<option> are given, they are all sent to the other side in the order
           listed on the command line.

       -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.

           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, the
           local ref that matches it is fast-forwarded using <src>. If the optional plus + is
           used, the local ref is updated even if it does not result in a fast-forward update.

               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.

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.

       Git supports ssh, git, http, and https protocols (in addition, ftp, and ftps can be used
       for fetching, but this is inefficient and deprecated; do not use it).

       The native transport (i.e. git:// URL) does no authentication and should be used with
       caution on unsecured networks.

       The following syntaxes may be used with them:

       ·   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/

       An alternative scp-like syntax may also be used with the ssh protocol:

       ·   [user@]host.xz:path/to/repo.git/

       This syntax is only recognized if there are no slashes before the first colon. This helps
       differentiate a local path that contains a colon. For example the local path foo:bar could
       be specified as an absolute path or ./foo:bar to avoid being misinterpreted as an ssh url.

       The ssh and git protocols additionally support ~username expansion:

       ·   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/

       For local repositories, also supported by Git natively, the following syntaxes may be
       used:

       ·   /path/to/repo.git/

       ·   file:///path/to/repo.git/

       These two syntaxes are mostly equivalent, except when cloning, when the former implies
       --local option. See git-clone(1) for details.

       When Git doesn’t know how to handle a certain transport protocol, it attempts to use the
       remote-<transport> remote helper, if one exists. To explicitly request a remote helper,
       the following syntax may be used:

       ·   <transport>::<address>

       where <address> may be a path, a server and path, or an arbitrary URL-like string
       recognized by the specific remote helper being invoked. See gitremote-helpers(1) for
       details.

       If there are a large number of similarly-named remote repositories and you want to use a
       different format for them (such that the URLs you use will be rewritten into URLs that
       work), you can create a configuration section of the form:

                   [url "<actual url base>"]
                           insteadOf = <other url base>

       For example, with this:

                   [url "git://git.host.xz/"]
                           insteadOf = host.xz:/path/to/
                           insteadOf = work:

       a URL like "work:repo.git" or like "host.xz:/path/to/repo.git" will be rewritten in any
       context that takes a URL to be "git://git.host.xz/repo.git".

       If you want to rewrite URLs for push only, you can create a configuration section of the
       form:

                   [url "<actual url base>"]
                           pushInsteadOf = <other url base>

       For example, with this:

                   [url "ssh://example.org/"]
                           pushInsteadOf = git://example.org/

       a URL like "git://example.org/path/to/repo.git" will be rewritten to
       "ssh://example.org/path/to/repo.git" for pushes, but pulls will still use the original
       URL.

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.

       All of these also allow you to omit the refspec from the command line because they each
       contain a refspec which git will use by default.

   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>

       The <pushurl> is used for pushes only. It is optional and defaults to <url>.

   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>

       Push: lines are used by git push and Pull: lines are used by git pull and git fetch.
       Multiple Push: and Pull: lines may be specified for additional branch mappings.

   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>

       <url> is required; #<head> is optional.

       Depending on the operation, git will use one of the following refspecs, if you don’t
       provide one on the command line. <branch> is the name of this file in $GIT_DIR/branches
       and <head> defaults to master.

       git fetch uses:

                   refs/heads/<head>:refs/heads/<branch>

       git push uses:

                   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.

       Typically such a variable may look like this:

           [remote "origin"]
                   fetch = +refs/heads/*:refs/remotes/origin/*

       This configuration is used in two ways:

       ·   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.

       The latter use of the remote.<repository>.fetch values can be overridden by giving the
       --refmap=<refspec> parameter(s) on the command line.

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.

       If left to accumulate, these stale references might make performance worse on big and busy
       repos that have a lot of branch churn, and e.g. make the output of commands like git
       branch -a --contains <commit> needlessly verbose, as well as impacting anything else
       that’ll work with the complete set of known references.

       These remote-tracking references can be deleted as a one-off with either of:

           # While fetching
           $ git fetch --prune <name>

           # Only prune, don't fetch
           $ git remote prune <name>

       To prune references as part of your normal workflow without needing to remember to run
       that, set fetch.prune globally, or remote.<name>.prune per-remote in the config. See git-
       config(1).

       Here’s where things get tricky and more specific. The pruning feature doesn’t actually
       care about branches, instead it’ll prune local <→ remote-references as a function of the
       refspec of the remote (see <refspec> and CONFIGURED REMOTE-TRACKING BRANCHES above).

       Therefore if the refspec for the remote includes e.g. refs/tags/*:refs/tags/*, or you
       manually run e.g. git fetch --prune <name> "refs/tags/*:refs/tags/*" it won’t be stale
       remote tracking branches that are deleted, but any local tag that doesn’t exist on the
       remote.

       This might not be what you expect, i.e. you want to prune remote <name>, but also
       explicitly fetch tags from it, so when you fetch from it you delete all your local tags,
       most of which may not have come from the <name> remote in the first place.

       So be careful when using this with a refspec like refs/tags/*:refs/tags/*, or any other
       refspec which might map references from multiple remotes to the same local namespace.

       Since keeping up-to-date with both branches and tags on the remote is a common use-case
       the --prune-tags option can be supplied along with --prune to prune local tags that don’t
       exist on the remote, and force-update those tags that differ. Tag pruning can also be
       enabled with fetch.pruneTags or remote.<name>.pruneTags in the config. See git-config(1).

       The --prune-tags option is equivalent to having refs/tags/*:refs/tags/* declared in the
       refspecs of the remote. This can lead to some seemingly strange interactions:

           # These both fetch tags
           $ git fetch --no-tags origin 'refs/tags/*:refs/tags/*'
           $ git fetch --no-tags --prune-tags origin

       The reason it doesn’t error out when provided without --prune or its config versions is
       for flexibility of the configured versions, and to maintain a 1=1 mapping between what the
       command line flags do, and what the configuration versions do.

       It’s reasonable to e.g. configure fetch.pruneTags=true in ~/.gitconfig to have tags pruned
       whenever git fetch --prune is run, without making every invocation of git fetch without
       --prune an error.

       Pruning tags with --prune-tags also works when fetching a URL instead of a named remote.
       These will all prune tags not found on 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.

       The status of the fetch is output in tabular form, with each line representing the status
       of a single ref. Each line is of the form:

            <flag> <summary> <from> -> <to> [<reason>]

       The status of up-to-date refs is shown only if the --verbose option is used.

       In compact output mode, specified with configuration variable fetch.output, if either
       entire <from> or <to> is found in the other string, it will be substituted with * in the
       other string. For example, master -> origin/master becomes master -> origin/*.

       flag
           A single character indicating the status of the ref:

           (space)
               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.

       summary
           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:

               $ git fetch origin

           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.

       ·   Using refspecs explicitly:

               $ git fetch origin +pu:pu maint:tmp

           This updates (or creates, as necessary) branches pu and tmp in the local repository by
           fetching from the branches (respectively) pu and maint from the remote repository.

           The pu branch will be updated even if it is does not fast-forward, because it is
           prefixed with a plus sign; tmp will not be.

       ·   Peek at a remote’s branch, without configuring the remote in your local repository:

               $ git fetch git://git.kernel.org/pub/scm/git/git.git maint
               $ git log FETCH_HEAD

           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)).

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.

       The known attack vectors are as follows:

        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.

BUGS

       Using --recurse-submodules can only fetch new commits in already checked out submodules
       right now. When e.g. upstream added a new submodule in the just fetched commits of the
       superproject the submodule itself can not be fetched, making it impossible to check out
       that submodule later without having to do a fetch again. This is expected to be fixed in a
       future Git version.

SEE ALSO

       git-pull(1)

GIT

       Part of the git(1) suite