Support nixpkgs shallow clone and make use of github pull/<pr>/merge ref

[azuwis]

Fix #267

[azuwis]

$ git clone --depth=1 https://github.com/NixOS/nixpkgs
$ cd nixpkgs
$ nix run github:Mic92/nixpkgs-review/pull/426/head -- pr 351518
$ git -c fetch.prune=false fetch --no-tags --force https://github.com/NixOS/nixpkgs --depth=1 master:refs/nixpkgs-review/0 pull/351518/merge:refs/nixpkgs-review/1
remote: Enumerating objects: 13, done.
remote: Counting objects: 100% (13/13), done.
remote: Compressing objects: 100% (6/6), done.
remote: Total 7 (delta 5), reused 1 (delta 0), pack-reused 0 (from 0)
Unpacking objects: 100% (7/7), 1.22 KiB | 1.22 MiB/s, done.
From https://github.com/NixOS/nixpkgs
 * [new branch]          master                 -> refs/nixpkgs-review/0
 * [new ref]             refs/pull/351518/merge -> refs/nixpkgs-review/1
$ git worktree add /home/azuwis/.cache/nixpkgs-review/pr-351518-20/nixpkgs 1825613c2c01eee21c60a3311777595248749e62
Preparing worktree (detached HEAD 1825613c2)
Updating files: 100% (43824/43824), done.
HEAD is now at 1825613c2 Merge 5860fb10e356ed9ec92378f4a476cd19cd0568c5 into abe4b94d28bfe39b0b2cfa7217af260b7bc8626e

$ nom build --file /nix/store/7ycribm20g147m94w6aa5j6xgkkdaljl-nixpkgs-review/lib/python3.12/site-packages/nixpkgs_review/nix/review-shell.nix --nix-path 'nixpkgs=/home/azuwis/.cache/nixpkgs-review/pr-351518-20/nixpkgs nixpkgs-overlays=/tmp/tmpitb204xx' --extra-experimental-features 'nix-command no-url-literals' --no-link --keep-going --no-allow-import-from-derivation --option build-use-sandbox relaxed --argstr local-system x86_64-linux --argstr nixpkgs-path /home/azuwis/.cache/nixpkgs-review/pr-351518-20/nixpkgs --argstr nixpkgs-config-path /tmp/tmpvja4ylsy.nix --argstr attrs-path /home/azuwis/.cache/nixpkgs-review/pr-351518-20/attrs.nix
Finished at 23:11:59 after 0s

Link to currently reviewing PR:
https://github.com/NixOS/nixpkgs/pull/351518

--------- Report for 'x86_64-linux' ---------
2 packages built:
git-up git-up.dist


$ /home/azuwis/.nix-profile/bin/nom-shell --argstr local-system x86_64-linux --argstr nixpkgs-path /home/azuwis/.cache/nixpkgs-review/pr-351518-20/nixpkgs --argstr nixpkgs-config-path /tmp/tmpvja4ylsy.nix --argstr attrs-path /home/azuwis/.cache/nixpkgs-review/pr-351518-20/attrs.nix --nix-path 'nixpkgs=/home/azuwis/.cache/nixpkgs-review/pr-351518-20/nixpkgs nixpkgs-overlays=/tmp/tmpitb204xx' /nix/store/7ycribm20g147m94w6aa5j6xgkkdaljl-nixpkgs-review/lib/python3.12/site-packages/nixpkgs_review/nix/review-shell.nix


[nix-shell:~/.cache/nixpkgs-review/pr-351518-20]$

[azuwis]

The CI tests should be fixed in latest push.

[Mic92]

In fact there is a race condition with this ref sometimes as github needs some time to compute it. But this is probably only relevant for CIs. So we should be unlikely to when humans run nixpkgs-review (except for @SuperSandro2000 maybe)

[Mic92]

@mergify queue

[mergify]

queue

🛑 The pull request has been merged manually

The pull request has been merged manually at 055465e

[azuwis]

I've found one regression, if the PR is merged, pull/<PR>/merge will be gone, and won't be able to run nixpkgs-review against a merged PR after this.

[Mic92]

Can we detect if /pull/<PR>/merge is available and otherwise fallback?

[azuwis]

We can use git ls-remote origin refs/pull/<PR>/merge, and checkout the output.