xref: /petsc/doc/developers/mrfork.md (revision f7bf64aeee44d4ea4cc3f90d11f02507f5582216) 
1(mr_fork)=
2
3# Checkout fork merge request branch
4
5`Developers` at times, need to checkout and build changes from a merge request fork branch. Any one of the following methods can be used:
6
7- Checkout `COMMIT-SHA` of the branch HEAD. It is available on the "Commits" tab of the merge request web page.
8
9  ```console
10  % git fetch origin <COMMIT-SHA>
11  % git checkout FETCH_HEAD
12  ```
13
14- Checkout branch using the repository `URL`. The `URL with branchname` is available as "Source branch" hyperlink on merge request web page.
15
16  ```console
17  % git fetch <URL> <branchname>
18  % git checkout FETCH_HEAD
19  ```
20
21- Setup a local Git clone to access the merge request branch via the `MR-NUMBER`. Here use the following in `.git/config`:
22
23  ```console
24  [remote "origin"]
25        url = https://gitlab.com/petsc/petsc.git
26        pushurl = git@gitlab.com:petsc/petsc.git
27        fetch = +refs/heads/*:refs/remotes/origin/*
28        fetch = +refs/merge-requests/*:refs/remotes/origin/merge-requests/*
29  ```
30
31  Now, the branch is available to checkout:
32
33  ```console
34  % git fetch
35  % git checkout origin/merge-requests/<MR-NUMBER>/head
36  ```
37
38# Commit and push changes to a merge request fork branch
39
40Only `Owners/Maintainers` can push commits to a merge request fork branch. Here, use the `ssh-URL` for the Git repository.
41
42```console
43% git fetch <ssh-URL> <branchname>
44% git checkout -b <branchname> FETCH_HEAD
45% git push -u <ssh-URL> <branchname>
46% (edit/commit)
47% git push
48```
49
50Notes:
51
52For example, with `merge request` at <https://gitlab.com/petsc/petsc/-/merge_requests/8619> we have:
53
54- `MR-NUMBER` = `8619`
55- `COMMIT-SHA` = `1b741c341f10772b6231f15a4abcef052bfe2d90` ("Copy commit SHA" of the HEAD commit from the "Commits" tab)
56- `URL with branchname` = `https://gitlab.com/paul.kuehner/petsc/-/tree/add-tao-get-constraints` ("Copy link" of "Source branch")
57- `URL` = `https://gitlab.com/paul.kuehner/petsc`
58- `ssh-URL` = `git@gitlab.com:paul.kuehner/petsc.git`
59- `branchname` = `add-tao-get-constraints`
60
61