Fwd: Submodules & worktree

Fwd: Submodules & worktree

[Ole Pinto]

Adding a worktree from a working copy with submodules doesn't work.

In the config file I have
    [submodule]
        recurse = true

It that's not present, I don't find the problem.

# Preparation

$ git --version
git version 2.20.1

$ cd /tmp/

$ git init main_repo
Initialized empty Git repository in /tmp/main_repo/.git/

$ git init repo_submod
Initialized empty Git repository in /tmp/repo_submod/.git/

$ cd repo_submod

$ echo Some text > file.txt

$ git add file.txt

$ git ci -m "First commit in subrepo"
[master (root-commit) ebc9325] First commit in subrepo
 1 file changed, 1 insertion(+)
 create mode 100644 file.txt

$ cd ../main_repo/

$ git submodule add /tmp/repo_submod submod
Cloning into '/tmp/main_repo/submod'...
done.

$ git ci -am "First commit, add submodule"
[master (root-commit) 695b3a1] First commit, add submodule
 2 files changed, 4 insertions(+)
 create mode 100644 .gitmodules
 create mode 160000 submod

# Problem 1 (can't run worktree add)

$ git worktree add ../wt -b new_branch
Preparing worktree (new branch 'new_branch')
fatal: exec '--super-prefix=submod/': cd to 'submod' failed: No such
file or directory
error: Submodule 'submod' could not be updated.
error: Submodule 'submod' cannot checkout new HEAD.
fatal: Could not reset index file to revision 'HEAD'.

The new directory (../wt) is created and removed (seen with strace).
The new branch is created and not removed.

# Problem 2 (submodule status seems not to detect some cases)

$ pwd
/tmp/main_repo

$ git submodule status
 ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod (heads/master)

$ rm submod/file.txt submod/.git

$ git submodule status
 ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod

So, I have a plain, empty directory where the submodule should be. Not
having any 'first char', I'd expect it to be checked out and up to
date. Is this expected?

Thanks a lot for the work!

Re: Submodules & worktree

[Mateusz Loskot]

On Fri, 1 Feb 2019 at 15:00, Ole Pinto <olepinto@gmail.com> wrote:
>
> Adding a worktree from a working copy with submodules doesn't work.
>
> In the config file I have
>     [submodule]
>         recurse = true
>

FYI, https://git-scm.com/docs/git-worktree#_bugs

"Multiple checkout in general is still experimental, and the support
for submodules is incomplete.
It is NOT recommended to make multiple checkouts of a superproject."

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net

Re: Submodules & worktree

[Philippe Blain]

Hi Ole,

> Le 1 févr. 2019 à 09:00, Ole Pinto <olepinto@gmail.com> a écrit :
> 
> Adding a worktree from a working copy with submodules doesn't work.
> 
> In the config file I have
>    [submodule]
>        recurse = true
> 
> It that's not present, I don't find the problem.

I also stumbled upon this bug and fixed it in 4782cf2ab6 (worktree: teach "add" to ignore submodule.recurse config, 2019-10-27), which was merged in 05fc6471e3 (Merge branch 'pb/no-recursive-reset-hard-in-worktree-add', 2019-12-01) and made it to Git 2.25.
`git worktree add` now works correctly in a project with submodules, and cd-ing to the new worktree directory and issuing `git submodule update` inits and clones the submodule(s) to .git/worktrees/<worktree-name>/modules/<submodule-name>, as it should.

I must warn you however that I discovered another bug that can happen with the submodule.recurse config when using worktrees with projects that have submodules. In short, issuing `git checkout` (or `git reset` or `git read-tree`) in one of the worktrees will leave the .git file in the submodule incorrectly pointing to the repository of the submodule in the main worktree, i.e. .git/modules/<submodule-name> instead of .git/worktrees/<worktree-name>/modules/<submodule-name>. I also fixed this bug [1], my patch series for this is currently in next. 

[1] https://github.com/gitgitgadget/git/pull/523

> # Problem 2 (submodule status seems not to detect some cases)
> 
> $ pwd
> /tmp/main_repo
> 
> $ git submodule status
> ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod (heads/master)
> 
> $ rm submod/file.txt submod/.git
> 
> $ git submodule status
> ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod
> 
> So, I have a plain, empty directory where the submodule should be. Not
> having any 'first char', I'd expect it to be checked out and up to
> date. Is this expected?
This is indeed not expected, and used to work correctly (the hash should be prefixed with a ‘-‘) in Git 2.12. This bevaviour regressed when `git submodule status` was ported to C in a9f8a37584 (submodule: port submodule subcommand 'status' from shell to C, 2017-10-06).
Another user reported this regression to the list recently and a patch series is in the works to fix it [2].

[2] https://lore.kernel.org/git/xmqqv9owbw5o.fsf@gitster-ct.c.googlers.com/

Cheers,
Philippe.

Re: Submodules & worktree

[Philippe Blain]

Hi Ole,

> Le 1 févr. 2019 à 09:00, Ole Pinto <olepinto@gmail.com> a écrit :
> 
> Adding a worktree from a working copy with submodules doesn't work.
> 
> In the config file I have
>   [submodule]
>       recurse = true
> 
> It that's not present, I don't find the problem.

I also stumbled upon this bug and fixed it in 4782cf2ab6 (worktree: teach "add" to ignore submodule.recurse config, 2019-10-27), which was merged in 05fc6471e3 (Merge branch 'pb/no-recursive-reset-hard-in-worktree-add', 2019-12-01) and made it to Git 2.25.
`git worktree add` now works correctly in a project with submodules, and cd-ing to the new worktree directory and issuing `git submodule update` inits and clones the submodule(s) to .git/worktrees/<worktree-name>/modules/<submodule-name>, as it should.

I must warn you however that I discovered another bug that can happen with the submodule.recurse config when using worktrees with projects that have submodules. In short, issuing `git checkout` (or `git reset` or `git read-tree`) in one of the worktrees will leave the .git file in the submodule incorrectly pointing to the repository of the submodule in the main worktree, i.e. .git/modules/<submodule-name> instead of .git/worktrees/<worktree-name>/modules/<submodule-name>. I also fixed this bug [1], my patch series for this is currently in next. 

[1] https://github.com/gitgitgadget/git/pull/523

> # Problem 2 (submodule status seems not to detect some cases)
> 
> $ pwd
> /tmp/main_repo
> 
> $ git submodule status
> ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod (heads/master)
> 
> $ rm submod/file.txt submod/.git
> 
> $ git submodule status
> ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod
> 
> So, I have a plain, empty directory where the submodule should be. Not
> having any 'first char', I'd expect it to be checked out and up to
> date. Is this expected?
This is indeed not expected, and used to work correctly (the hash should be prefixed with a ‘-‘) in Git 2.12. This bevaviour regressed when `git submodule status` was ported to C in a9f8a37584 (submodule: port submodule subcommand 'status' from shell to C, 2017-10-06).
Another user reported this regression to the list recently and a patch series is in the works to fix it [2].

[2] https://lore.kernel.org/git/xmqqv9owbw5o.fsf@gitster-ct.c.googlers.com/

Cheers,
Philippe.

Re: Submodules & worktree

[Philippe Blain]

Hi Ole,

> Le 1 févr. 2019 à 09:00, Ole Pinto <olepinto@gmail.com> a écrit :
> 
> Adding a worktree from a working copy with submodules doesn't work.
> 
> In the config file I have
>   [submodule]
>       recurse = true
> 
> It that's not present, I don't find the problem.

I also stumbled upon this bug and fixed it in 4782cf2ab6 (worktree: teach "add" to ignore submodule.recurse config, 2019-10-27), which was merged in 05fc6471e3 (Merge branch 'pb/no-recursive-reset-hard-in-worktree-add', 2019-12-01) and made it to Git 2.25.
`git worktree add` now works correctly in a project with submodules, and cd-ing to the new worktree directory and issuing `git submodule update` inits and clones the submodule(s) to .git/worktrees/<worktree-name>/modules/<submodule-name>, as it should.

I must warn you however that I discovered another bug that can happen with the submodule.recurse config when using worktrees with projects that have submodules. In short, issuing `git checkout` (or `git reset` or `git read-tree`) in one of the worktrees will leave the .git file in the submodule incorrectly pointing to the repository of the submodule in the main worktree, i.e. .git/modules/<submodule-name> instead of .git/worktrees/<worktree-name>/modules/<submodule-name>. I also fixed this bug [1], my patch series for this is currently in next. 

[1] https://github.com/gitgitgadget/git/pull/523

> # Problem 2 (submodule status seems not to detect some cases)
> 
> $ pwd
> /tmp/main_repo
> 
> $ git submodule status
> ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod (heads/master)
> 
> $ rm submod/file.txt submod/.git
> 
> $ git submodule status
> ebc9325f7b19164c9bdfd05263481ded66d7bd7d submod
> 
> So, I have a plain, empty directory where the submodule should be. Not
> having any 'first char', I'd expect it to be checked out and up to
> date. Is this expected?
This is indeed not expected, and used to work correctly (the hash should be prefixed with a ‘-‘) in Git 2.12. This bevaviour regressed when `git submodule status` was ported to C in a9f8a37584 (submodule: port submodule subcommand 'status' from shell to C, 2017-10-06).
Another user reported this regression to the list recently and a patch series is in the works to fix it [2].

[2] https://lore.kernel.org/git/xmqqv9owbw5o.fsf@gitster-ct.c.googlers.com/

Cheers,
Philippe.