如何在repo中更新所有git子模块(两种方法做两种完全不同的事情!)

快速的总结

# Option 1: as a **user** of the outer repo, pull the latest changes of the
# sub-repos as previously specified (pointed to as commit hashes) by developers
# of this outer repo.
# - This recursively updates all git submodules to their commit hash pointers as
#   currently committed in the outer repo.
git submodule update --init --recursive

# Option 2. As a **developer** of the outer repo, update all subrepos to force
# them each to pull the latest changes from their respective upstreams (ex: via
# `git pull origin main` or `git pull origin master`, or similar, for each
# sub-repo). 
git submodule update --init --recursive --remote

# now add and commit these subrepo changes
git add -A
git commit -m "Update all subrepos to their latest upstream changes"

细节

Option 1: as a user of the outer repo, trying to get all submodules into the state intended by the developers of the outer repo: git submodule update --init --recursive Option 2: as a developer of the outer repo, trying to update all submodules to the latest commit pushed to the default branch of each of their remote repos (ie: update all subrepos to the latest state intended by the developers of each subrepo): git submodule update --init --recursive --remote ...in place of using git submodule foreach --recursive git pull origin master or git submodule foreach --recursive git pull origin main.

在我看来，上述两个选项的最佳答案是不要使用我在其他一些答案中看到的——merge和——force选项。

上述选项的解释:

the --init part above initializes the submodule in case you just cloned the repo and haven't done that yet --recursive does this for submodules within submodules, recursively down forever and --remote says to update the submodule to the latest commit on the default branch on the default remote for the submodule. It is like doing git pull origin master or git pull origin main in most cases, for example, for each submodule. If you want to update to the commit specified by the outer-most repo (super repo) instead, leave --remote off.

Git子模块foreach——递归Git pull(不要用这个——它经常失败)vs Git子模块update——递归——远程(用这个!——它总是有效的)

我在这个答案下面留下了以下评论。我认为它们很重要，所以我也把它们放在我的回答中。

Basically, for some situations, git submodule foreach --recursive git pull might work. For others, git submodule foreach --recursive git pull origin master might be what you need instead. For others, git submodule foreach --recursive git pull origin main might be what you need. And for others still, none of those might work! You might need git submodule foreach --recursive git pull upstream develop, for instance. OR, even worse, there might not be any git submodule foreach command which works for your outer repo, as each submodule might require a different command to update itself from its default remote and default branch. In all cases I can find, however, this does work, including for all cases you might use one of the several git submodule foreach commands I just presented above. So, use this instead:

git submodule update --recursive --remote

不管怎样，下面是我对这个答案的一些评论:

(1/4) @DavidZ, a lot of people think that git submodule foreach git pull and git submodule update --remote are the same thing, with the latter simply being the newer command. They aren't the same thing, however. git submodule foreach git pull will fail under multiple circumstances for which git submodule update --remote works just fine! If your submodule points to a commit hash that doesn't have a branch pointing to it, which is frequently the case in real-life development where you want a particular version of the submodule for your outer repo, then that submodule... (2/4)...is in a detached HEAD state. In this case, git submodule foreach git pull fails to run git pull on that submodule since a detached HEAD cannot have an upstream branch. git submodule update --remote, however, works just fine! It appears to call git pull origin main on that submodule if origin is the default remote and main is the default branch on that default remote, or git pull origin master, for instance, if origin is the default remote but master is the default branch. (3/4) Furthemore, git submodule foreach git pull origin master will even fail in many cases where git submodule update --remote works just fine, since many submodules use master as the default branch, and many other submodules use main as the default branch since GitHub changed from master to main recently in order to get away from terms related to slavery in the United States ("master" and "slave"). (4/4) So, I added the explicit remote and branch to make it more clear that they are frequently needed, and to remind people that git pull is frequently not enough, and git pull origin master may not work, and git pull origin main may work when the former doesn't, but also may not even work, and that none of them by themselves are the same as git submodule update --remote, since that latter command is smart enough to just do git pull <default_remote> <default_branch> for you for each submodule, apparently adjusting the remote and branch as necessary for each submodule.

相关，及其他研究

如何找到一个回购的主要分支:https://stackoverflow.com/a/49384283/4561887 如何通过git子模块foreach运行自定义命令来更新每个subrepo <cmd>: https://stackoverflow.com/a/45744725/4561887 Man git子模块-然后搜索foreach，——remote等。

对我来说，所有的git子模块都不工作。但这个方法奏效了:

cd <path/to/submodule>
git pull

它下载并因此更新第三方回购。 然后

cd <path/to/repo>
git commit -m "update latest version" <relative_path/to/submodule>
git push

它更新了您的远程回购(与最后一次提交的链接repo@xxxxxx)。

Git 1.8.2提供了一个新选项——remote，它将启用这种行为。运行

git submodule update --remote --merge

将从每个子模块的上游获取最新的更改，将它们合并到子模块中，并检出子模块的最新修订。如文档所述:

——远程 此选项仅对update命令有效。与其使用超项目记录的SHA-1来更新子模块，不如使用子模块的远程跟踪分支的状态。

这相当于在每个子模块中运行git pull <remote> <default_branch>(通常是git pull origin master或git pull origin main)，这通常正是你想要的。

如果你想为每个子模块签出主分支，你可以使用下面的命令:

git submodule foreach git checkout master

git子模块update命令实际上告诉git，您希望每个子模块都检出在超项目索引中已经指定的提交。如果您希望将子模块更新为远程可用的最新提交，则需要直接在子模块中执行此操作。

总结一下:

# Get the submodule initially
git submodule add ssh://bla submodule_dir
git submodule init

# Time passes, submodule upstream is updated
# and you now want to update

# Change to the submodule directory
cd submodule_dir

# Checkout desired branch
git checkout master

# Update
git pull

# Get back to your project root
cd ..

# Now the submodules are in the state you want, so
git commit -am "Pulled down update to submodule_dir"

或者，如果你是个大忙人:

git submodule foreach git pull origin master

注意，虽然更新子模块提交的现代形式是:

git submodule update --recursive --remote --force

请参阅Gabriel Staples的另一种回答，不使用“合并”力。

——force选项允许发生签出，即使在包含存储库的索引中指定的提交已经与子模块中签出的提交匹配。

在这种情况下，——merge选项似乎没有必要:“记录在超项目中的提交将被合并到子模块中的当前分支中。”

旧的形式是:

git submodule foreach --quiet git pull --quiet origin

除了……第二种形式并不是真正的“安静”。

参见提交a282f5a (12 Apr 2019) by nguyThái ngeconc Duy (pclouds)。 (由Junio C Hamano—gitster—在commit f1c9f6c中合并，2019年4月25日)

子模块foreach:修复“<命令>—quiet”不被尊重

Robin reported that git submodule foreach --quiet git pull --quiet origin is not really quiet anymore. It should be quiet before fc1b924 (submodule: port submodule subcommand 'foreach' from shell to C, 2018-05-10, Git v2.19.0-rc0) because parseopt can't accidentally eat options then. "git pull" behaves as if --quiet is not given. This happens because parseopt in submodule--helper will try to parse both --quiet options as if they are foreach's options, not git-pull's. The parsed options are removed from the command line. So when we do pull later, we execute just this git pull origin When calling submodule helper, adding "--" in front of "git pull" will stop parseopt for parsing options that do not really belong to submodule--helper foreach. PARSE_OPT_KEEP_UNKNOWN is removed as a safety measure. parseopt should never see unknown options or something has gone wrong. There are also a couple usage string update while I'm looking at them. While at it, I also add "--" to other subcommands that pass "$@" to submodule--helper. "$@" in these cases are paths and less likely to be --something-like-this. But the point still stands, git-submodule has parsed and classified what are options, what are paths. submodule--helper should never consider paths passed by git-submodule to be options even if they look like one.

Git 2.23(2019年Q3)修复了另一个问题:当“——recursive”选项正在使用时，“Git submodule foreach”没有保护传递给命令的命令行选项，以便在每个子模块中正确运行。

参见莫里亚十四行诗(momoson)的commit 30db18b(2019年6月24日)。 (由Junio C Hamano—gitster—在commit 968eecb中合并，2019年7月9日)

子模块foreach:修复选项的递归

Calling: git submodule foreach --recursive <subcommand> --<option> leads to an error stating that the option --<option> is unknown to submodule--helper. That is of course only, when <option> is not a valid option for git submodule foreach. The reason for this is, that above call is internally translated into a call to submodule--helper: git submodule--helper foreach --recursive \ -- <subcommand> --<option> This call starts by executing the subcommand with its option inside the first level submodule and continues by calling the next iteration of the submodule foreach call git --super-prefix <submodulepath> submodule--helper \ foreach --recursive <subcommand> --<option> inside the first level submodule. Note that the double dash in front of the subcommand is missing. This problem starts to arise only recently, as the PARSE_OPT_KEEP_UNKNOWN flag for the argument parsing of git submodule foreach was removed in commit a282f5a. Hence, the unknown option is complained about now, as the argument parsing is not properly ended by the double dash. This commit fixes the problem by adding the double dash in front of the subcommand during the recursion.

请注意，在Git 2.29 (Q4 2020)之前，“Git子模块更新—quiet”(man)并没有压制底层的“rebase”和“pull”命令。

参见Theodore Dubois (tbodt)提交3ad0401(2020年9月30日)。 (由Junio C Hamano - gitster -在commit 300cd14中合并，2020年10月5日)

子模块更新:在merge/rebase下使用"——quiet" 署名:Theodore Dubois

Commands such as $ git pull --rebase --recurse-submodules --quiet produce non-quiet output from the merge or rebase. Pass the --quiet option down when invoking "rebase" and "merge". Also fix the parsing of git submodule update(man) -v. When e84c3cf3 ("git-submodule.sh: accept verbose flag in cmd_update to be non-quiet", 2018-08-14, Git v2.19.0-rc0 -- merge) taught "git submodule update"(man) to take "--quiet", it apparently did not know how ${GIT_QUIET:+--quiet} works, and reviewers seem to have missed that setting the variable to "0", rather than unsetting it, still results in "--quiet" being passed to underlying commands.

在Git 2.38 (Q3 2022)中，Git -submodule.sh已准备好被转换为内置，这意味着存在上述问题的子模块-helper将被淡出。

参见commit 5b893f7, commit 2eec463, commit 8f12108, commit 36d4516, commit 6e556c4, commit 0d68ee7, commit d9c7f69, commit da3aae9, commit 757d092, commit 960fad9, commit 8577525 (28 Jun 2022) by Ævar Arnfjörð Bjarmason (avar)。 参见commit b788fc6(2022年6月28日)，作者Glen Choo (chooglen)。 (由Junio C Hamano—gitster—在commit 361cbe6中合并，2022年7月14日)

git-submodule.sh:使用$quiet，而不是$GIT_QUIET 署名:Ævar Arnfjörð Bjarmason

Remove the use of the "$GIT_QUIET" variable in favor of our own "$quiet", ever since b3c5f5c ("submodule: move core cmd_update() logic to C", 2022-03-15, Git v2.36.0-rc0 -- merge) we have not used the "say" function in git-sh-setup.sh, which is the only thing that's affected by using "GIT_QUIET". We still want to support --quiet for our own use though, but let's use our own variable for that. Now it's obvious that we only care about passing "--quiet" to git submodule--helper, and not to change the output of any "say" invocation.