bug#50026: Specify a pull-request in --with-branch package transformations

[zimoun]

Hi,

On Tue, 14 Sep 2021 at 09:43, Ludovic Courtès  wrote:
> Philippe SWARTVAGHER  skribis:
>
>> guix build chameleon --with-branch=chameleon=merge-requests/262/head
>> guix build: erreur : impossible de récupérer la branche «
>> merge-requests/262/head » depuis
>> https://gitlab.inria.fr/solverstack/chameleon : cannot locate
>> remote-tracking branch 'origin/merge-requests/262/head'
>> ```
>>
>> While commands stated in the documentation work well:
>>
>> ```bash
>>
>> git clone https://gitlab.inria.fr/solverstack/chameleon && cd chameleon
>> git fetch origin merge-requests/262/head

> Any idea what makes this branches “special” from a Git viewpoint?

I do not know but the branch is not listed after a fresh clone:

--8<---cut here---start->8---
$ git clone https://gitlab.inria.fr/solverstack/chameleon
$ cd chameleon
$ git branch -av
* master   be19cc46 Merge branch 'fix-warning' into 'master'
  remotes/origin/HEAD  -> origin/master
  remotes/origin/masterbe19cc46 Merge branch 'fix-warning' into 'master'
  remotes/origin/release-0.9.2 d2b4cab3 Fix artifact
  remotes/origin/release-1.0.0 da81c248 Update ChangeLog
  remotes/origin/release-1.1.0 4db899ca Merge branch 'next_release' into 
'master'
--8<---cut here---end--->8---

So I guess the GitLab Merge Requests are “special” branches.  Well, I do not 
know
if checking the API makes sense ;-)

   


All the best,
simon

bug#50026: Specify a pull-request in --with-branch package transformations

[Ludovic Courtès]

Hi!

Philippe SWARTVAGHER  skribis:

> guix build chameleon --with-branch=chameleon=merge-requests/262/head
>
> ```
>
> (with 262 being the pull-request I'm interested in) However, this fails:
>
> ```
>
> guix build: erreur : impossible de récupérer la branche «
> merge-requests/262/head » depuis
> https://gitlab.inria.fr/solverstack/chameleon : cannot locate
> remote-tracking branch 'origin/merge-requests/262/head'
> ```
>
> While commands stated in the documentation work well:
>
> ```bash
>
> git clone https://gitlab.inria.fr/solverstack/chameleon && cd chameleon
>
> git fetch origin merge-requests/262/head:mr-262
>
> git checkout mr-262

Any idea what makes this branches “special” from a Git viewpoint?

Guix uses libgit2 (via Guile-Git); perhaps there’s a feature here that
libgit2 doesn’t support, or perhaps there’s an additional step to make
to make those branches visible?

Thanks,
Ludo’.

bug#50026: Specify a pull-request in --with-branch package transformations

[Philippe SWARTVAGHER]

Le 12/08/2021 à 17:30, raingloom a écrit :
> How is this different compared to just using the git URL and branch that
> the pull request is from?
>
> For example, here we have a merge request:
> https://gitlab.com/guile-git/guile-git/-/merge_requests/30
> From this repo:
> https://gitlab.com/plattfot/guile-git
> and this branch:
> git_ignore_path_is_ignored
>
> This is how merge requests work, there is always a (pretty easy to
> find) source repo and branch that should be merged into a branch of the
> target repo.
>
> This is how you would build it in this case:
> guix build \
> --with-git-url=guile-git=https://gitlab.com/plattfot/guile-git \
> --with-branch=guile-git=git_ignore_path_is_ignored guile-git
>
> Someone could make a script that extracts this information from the
> various git forges (Gitea, GitLab, GitHub, etc), but all you get is
> that you can copy one URL instead of one URL and one branch name.
When the fork repository is private and you don't have access to it, you
can't use --with-git-url=package=https://someforge/user/private-fork
because you won't be allowed to. However, you can have access to the
pull request made in the public origin repository.
>
> I'm not aware of any standard way to access merge requests that would
> work across all git forges, 

Me neither, but maybe just asking Git to fetch all exisitng remote
references (including these kind of special references representing pull
requests) before trying to switch to the asked pull-request/branch may
do the trick (it's maybe more complex than that, I don't know).


> so IMHO the implementation complexity is
> not worth it for such a tiny improvement. There is more important work.
Sure, it was just to point out this use-case, and since other tools can
handle, maybe it is not so hard to implement. I'm totally aware this is
a non-prioritary corner-case.

-- 
Philippe SWARTVAGHER

PhD Student
TADaaM team, Inria Bordeaux Sud-Ouest

bug#50026: Specify a pull-request in --with-branch package transformations

[raingloom]

On Thu, 12 Aug 2021 11:38:38 +0200
Philippe SWARTVAGHER  wrote:

> Hello,
> 
> A nice feature would be to be able to use a pull-request as branch to
> specify in the `--with-branch` transformation option.
> 
> A use-case is to use a pull-request coming from a private fork, thus
> we can't use the combination `--with-git-url= with-branch=`.
> 
> 
> As an example, if I follow
> https://gitlab.inria.fr/help/user/project/merge_requests/reviews/index.md#checkout-merge-requests-locally-through-the-head-ref,
> I should be able to do something like:
> 
> ```bash
> 
> guix build chameleon --with-branch=chameleon=merge-requests/262/head
> 
> ```
> 
> (with 262 being the pull-request I'm interested in) However, this
> fails:
> 
> ```
> 
> guix build: erreur : impossible de récupérer la branche «
> merge-requests/262/head » depuis
> https://gitlab.inria.fr/solverstack/chameleon : cannot locate
> remote-tracking branch 'origin/merge-requests/262/head'
> ```
> 
> While commands stated in the documentation work well:
> 
> ```bash
> 
> git clone https://gitlab.inria.fr/solverstack/chameleon && cd
> chameleon
> 
> git fetch origin merge-requests/262/head:mr-262
> 
> git checkout mr-262
> 
> ```
> 
> I guess the fetch step is lacking in the way Guix handles the
> `--with-branch` transformation.
> 
> 
> FYI, Ansible is able to do things like that (see
> https://docs.ansible.com/ansible/latest/collections/ansible/builtin/git_module.html),
> by combining options `refspec` and `version`.
> 
> 
> I'm aware a workaround is to download the patch corresponding to the
> pull-request and using `--with-patch`, however handling it directly
> with `--with-branch` would be more handy !
> 
> Thanks,
> 

How is this different compared to just using the git URL and branch that
the pull request is from?

For example, here we have a merge request:
https://gitlab.com/guile-git/guile-git/-/merge_requests/30
From this repo:
https://gitlab.com/plattfot/guile-git
and this branch:
git_ignore_path_is_ignored

This is how merge requests work, there is always a (pretty easy to
find) source repo and branch that should be merged into a branch of the
target repo.

This is how you would build it in this case:
guix build \
--with-git-url=guile-git=https://gitlab.com/plattfot/guile-git \
--with-branch=guile-git=git_ignore_path_is_ignored guile-git

Someone could make a script that extracts this information from the
various git forges (Gitea, GitLab, GitHub, etc), but all you get is
that you can copy one URL instead of one URL and one branch name.

I'm not aware of any standard way to access merge requests that would
work across all git forges, so IMHO the implementation complexity is
not worth it for such a tiny improvement. There is more important work.

bug#50026: Specify a pull-request in --with-branch package transformations

[Philippe SWARTVAGHER]

Hello,

A nice feature would be to be able to use a pull-request as branch to
specify in the `--with-branch` transformation option.

A use-case is to use a pull-request coming from a private fork, thus we
can't use the combination `--with-git-url= with-branch=`.


As an example, if I follow
https://gitlab.inria.fr/help/user/project/merge_requests/reviews/index.md#checkout-merge-requests-locally-through-the-head-ref,
I should be able to do something like:

```bash

guix build chameleon --with-branch=chameleon=merge-requests/262/head

```

(with 262 being the pull-request I'm interested in) However, this fails:

```

guix build: erreur : impossible de récupérer la branche «
merge-requests/262/head » depuis
https://gitlab.inria.fr/solverstack/chameleon : cannot locate
remote-tracking branch 'origin/merge-requests/262/head'
```

While commands stated in the documentation work well:

```bash

git clone https://gitlab.inria.fr/solverstack/chameleon && cd chameleon

git fetch origin merge-requests/262/head:mr-262

git checkout mr-262

```

I guess the fetch step is lacking in the way Guix handles the
`--with-branch` transformation.


FYI, Ansible is able to do things like that (see
https://docs.ansible.com/ansible/latest/collections/ansible/builtin/git_module.html),
by combining options `refspec` and `version`.


I'm aware a workaround is to download the patch corresponding to the
pull-request and using `--with-patch`, however handling it directly with
`--with-branch` would be more handy !

Thanks,

-- 
Philippe SWARTVAGHER

PhD Student
TADaaM team, Inria Bordeaux Sud-Ouest