# git submodule add fails when using both --branch and --depth 3 messages from 2017-09-30 to 2017-10-02. Participants: Thadeus Fleming, Stefan Beller, Jonathan Nieder. Thread: https://gitlist.dev/t/46864 ## Thadeus Fleming, 2017-09-30 17:20 Subject: git submodule add fails when using both --branch and --depth Message-ID: URL: https://gitlist.dev/e/CAA4Wa2sVddG_SS70Dy_womGLKW0ipAjsxR4g%2ByjMKscjErRjvQ%40mail.gmail.com ``` I'm running git 2.14.2 on Ubuntu 16.04. Compare the behavior of > git clone --branch pu --depth 1 https://github.com/git/git git-pu which clones only the latest commit of the pu branch and > mkdir tmp && cd tmp && git init > git submodule add --branch pu --depth 1 https://github.com/git/git \ git-pu which gives the error fatal: 'origin/pu' is not a commit and a branch 'pu' cannot be created from it Unable to checkout submodule 'git-pu' Investigating further, there is indeed only one commit in the local repo: > cd git-pu > git log --oneline | wc -l 1 But that commit is the head of master. > git branch -a * master remotes/origin/master remotes/origin/HEAD -> origin/master This appears to be because git-submodule--helper does not accept a --branch option. Using the --depth N option causes it to only clone N commits from the default branch, which generally do not include the desired branch. Thus, the next step, git checkout -f -q -B "$branch" "origin/$branch" fails, and provides the rather confusing error message above. I'd suggest that git-submodule--helper learn a --branch option consistent with git clone, and if that is impossible, that git submodule add rejects the simultaneous use of both the --branch and --depth options. --tjf ``` ## Stefan Beller, 2017-10-02 19:55 Subject: Re: git submodule add fails when using both --branch and --depth Message-ID: URL: https://gitlist.dev/e/CAGZ79kYt1rC5D%3DGk8Ei1FmwF_zqK2AQgP_TQFHsV-NGHfVgOKA%40mail.gmail.com In-Reply-To: ``` On Sat, Sep 30, 2017 at 10:20 AM, Thadeus Fleming wrote: > I'm running git 2.14.2 on Ubuntu 16.04. > > Compare the behavior of > >> git clone --branch pu --depth 1 https://github.com/git/git git-pu > > which clones only the latest commit of the pu branch and > >> mkdir tmp && cd tmp && git init >> git submodule add --branch pu --depth 1 https://github.com/git/git \ > git-pu > > which gives the error > > fatal: 'origin/pu' is not a commit and a branch 'pu' cannot be created > from it > Unable to checkout submodule 'git-pu' > > Investigating further, there is indeed only one commit in the local repo: > >> cd git-pu >> git log --oneline | wc -l > 1 > > But that commit is the head of master. > >> git branch -a > * master remotes/origin/master > remotes/origin/HEAD -> origin/master > > This appears to be because git-submodule--helper does not accept a > --branch option. Using the --depth N option causes it to only clone N > commits from the default branch, which generally do not include the > desired branch. Thus, the next step, > > git checkout -f -q -B "$branch" "origin/$branch" > > fails, and provides the rather confusing error message above. > > I'd suggest that git-submodule--helper learn a --branch option > consistent with git clone, and if that is impossible, that > git submodule add rejects the simultaneous use of both the --branch and > --depth options. Adding the branch field to the submodule helper is a great idea. > > > > --tjf ``` ## Jonathan Nieder, 2017-10-02 22:08 Subject: Re: git submodule add fails when using both --branch and --depth Message-ID: <20171002220844.GQ19555@aiede.mtv.corp.google.com> URL: https://gitlist.dev/e/20171002220844.GQ19555%40aiede.mtv.corp.google.com In-Reply-To: ``` Hi, Thadeus Fleming wrote: > I'm running git 2.14.2 on Ubuntu 16.04. > > Compare the behavior of > >> git clone --branch pu --depth 1 https://github.com/git/git git-pu > > which clones only the latest commit of the pu branch and Yes. >> mkdir tmp && cd tmp && git init >> git submodule add --branch pu --depth 1 https://github.com/git/git \ > git-pu > > which gives the error > > fatal: 'origin/pu' is not a commit and a branch 'pu' cannot be created from it > Unable to checkout submodule 'git-pu' As a side note (you are using "git submodule add --depth", not "git submodule update --depth"), I suspect that "submodule update --depth" may not always do what people expect. With add --depth, I agree with your expectation and after your fix everything should work fine. But with update --depth, consider the following sequence of steps: 1. I create a repository "super" with submodule "sub" and publish both. 2. I make a couple commits to "sub" and a commit to "super" making use of those changes and want to publish them. 3. I use "git push --recurse-submodules" to publish my commits to "sub" and "super": a. First it pushes to "sub". b. Then it pushes to "super". Between steps 3(a) and 3(b), a person can still "git clone --recurse-submodules" the "super" repository. The repository "super" does not have my change yet and "sub" does, but that is not a problem, since commands like "git checkout --recurse-submodules" and "git submodule update" know to check out the commit *before* my change in the submodule. But between steps 3(a) and 3(b), "git submodule update --depth=1" would not work. It would fetch the submodule with depth 1 and then try to check out a commit that is deeper in history. So I think there's more thinking needed there. That's all a tangent to your report about add --depth, though. Thanks, Jonathan ```