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。