Previously, when updating multiple packages, we just updated them in arbitrary order. However, when some of those packages depended on each other, it could happen that some of the intermediary commits would not build because of version constraints on dependencies.
If we want each commit in the history to build when feasible, we need to consider four different scenarios:
1. Updated dependant is compatible with both the old and the new version of the dependency. Order of commits does not matter. But updating dependents first (i.e. reverse topological order) is useful since it allows building each package on the commit that updates it with minimal rebuilds.
2. Updated dependant raises the minimal dependency version. Dependency needs to be updated first (i.e. topological order).
3. Old dependant sets the maximal dependency version. Dependant needs to be updated first (i.e. reverse topological order).
4. Updated dependant depends on exact version of dependency and they are expected to be updated in lockstep. The earlier commit will be broken no matter the order.
This change allows selecting the order of updates to facilitate the first three scenarios. Since most package sets only have loose version constraints, the reverse topological order will generally be the most convenient. In major package set updates like bumping GNOME release, there will be exceptions (e.g. libadwaita typically requires GTK 4 from the same release) but those were probably in broken order before as well.
The downside of this feature is that it is quite slow – it requires instantiating each package and then querying Nix store for requisites.
It may also fail to detect dependency if there are multiple variants of the package and dependant uses a different one than the canonical one.
Testing with:
env GNOME_UPDATE_STABILITY=unstable NIX_PATH=nixpkgs=$HOME/Projects/nixpkgs nix-shell maintainers/scripts/update.nix --arg predicate '(path: pkg: path == ["gnome-shell"] || path == ["mutter"] || path == ["glib"] || path == ["gtk3"] || path == ["pango"] || path == ["gnome-text-editor"])' --argstr order reverse-topological --argstr commit true --argstr max-workers 4
After final improvements to the official formatter implementation,
this commit now performs the first treewide reformat of Nix files using it.
This is part of the implementation of RFC 166.
Only "inactive" files are reformatted, meaning only files that
aren't being touched by any PR with activity in the past 2 months.
This is to avoid conflicts for PRs that might soon be merged.
Later we can do a full treewide reformat to get the rest,
which should not cause as many conflicts.
A CI check has already been running for some time to ensure that new and
already-formatted files are formatted, so the files being reformatted here
should also stay formatted.
This commit was automatically created and can be verified using
nix-build a08b3a4d19.tar.gz \
--argstr baseRev b32a094368
result/bin/apply-formatting $NIXPKGS_PATH
After final improvements to the official formatter implementation,
this commit now performs the first treewide reformat of Nix files using it.
This is part of the implementation of RFC 166.
Only "inactive" files are reformatted, meaning only files that
aren't being touched by any PR with activity in the past 2 months.
This is to avoid conflicts for PRs that might soon be merged.
Later we can do a full treewide reformat to get the rest,
which should not cause as many conflicts.
A CI check has already been running for some time to ensure that new and
already-formatted files are formatted, so the files being reformatted here
should also stay formatted.
This commit was automatically created and can be verified using
nix-build a08b3a4d19.tar.gz \
--argstr baseRev 78e9caf153
result/bin/apply-formatting $NIXPKGS_PATH
