Joachim Breitner's Homepage

Because it seemed useful, and it seems it did not exist yet, I created a small tool called git-multisect. You point it to a git repo, give it a version range and a command to run, and it will list those commits that affect the output of the command.

Here is an example (with a slightly complex invocation):

$ git-multisect.py \
	-C ~/build/nixpkgs \
	-f $(nix flake metadata ~/nixos --json|jq -r ".locks.nodes[.locks.nodes[.locks.root].inputs.nixpkgs].locked.rev") \
	-t release-22.11 \
	-c 'nix path-info --derivation '\
	   '~/nixos#nixosConfigurations.richard.config.system.build.toplevel '\
	   '--no-update-lock-file '\
	   '--override-input nixpkgs ~/"build/nixpkgs?rev=$REV"' \
	--hide-stderr --log-option=--pretty=medium
Found 39 commits
[39 total,  0 relevant,  0 irrelevant,  0 skipped, 39 unknown] inspecing 2fb7d74 ...
[39 total,  0 relevant,  0 irrelevant,  0 skipped, 39 unknown] inspecing 569163e ...
[39 total,  0 relevant,  0 irrelevant,  0 skipped, 39 unknown] inspecing 5642ce8 ...
[39 total,  0 relevant,  0 irrelevant,  0 skipped, 39 unknown] inspecing e0c8cf8 ...
[39 total,  0 relevant,  1 irrelevant,  8 skipped, 30 unknown] inspecing 89d0361 ...
[39 total,  0 relevant,  1 irrelevant,  8 skipped, 30 unknown] inspecing d1c7e63 ...
[39 total,  0 relevant,  2 irrelevant,  9 skipped, 28 unknown] inspecing e6d5772 ...
[39 total,  0 relevant,  3 irrelevant,  9 skipped, 27 unknown] inspecing a099526 ...
[39 total,  1 relevant,  4 irrelevant,  9 skipped, 25 unknown] inspecing 854312a ...
[39 total,  1 relevant,  5 irrelevant, 10 skipped, 23 unknown] inspecing 95043dc ...
[39 total,  1 relevant,  6 irrelevant, 10 skipped, 22 unknown] inspecing 0cf4274 ...
[39 total,  2 relevant,  8 irrelevant, 29 skipped,  0 unknown] done

commit a0995268af8ba0336a81344a3bf6a50d6d6481b2
Author: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Date:   Sat Feb 18 10:45:11 2023 -0800

    linux_{5_15,6_1}: revert patch to fix Equinix Metal bonded networking with `ice` driver (#216955)
…
commit 0cf4274b5d06325bd16dbf879a30981bc283e58a
Merge: 95043dc713d 532f3aa6052
Author: Pierre Bourdon <delroth@gmail.com>
Date:   Sun Feb 19 23:37:48 2023 +0900

    Merge pull request #217121 from NixOS/backport-216463-to-release-22.11

    [Backport release-22.11] sudo: 1.9.12p2 -> 1.9.13

As you can see it tries to be clever to not even look at commits that come between two commits where the output is equal (like git-bisect).

Over at https://github.com/nomeata/git-multisect you’ll find more explanations and examples. Hope you’ll maybe remember this when you find you’ll need it, and that it will prove to be useful.