gateFlake judges the formatting check right after the lock moves, but the
fmt area runs last, so the new toolchain's formatting had not been applied
yet and the flake area dropped itself every run.
flake-checks moved its nix formatter from nixpkgs-fmt to nixfmt, so every
.nix file failed the formatting check. gateFlake only ran `nix eval`, so
that reached the final gate, which drops the newest commit first and had
to pop all eleven areas above it to get there. Three hours, nothing
shipped.
go env GOVERSION reports the toolchain the go command switched to, so a
go.mod that had outrun nixpkgs read back as a nixpkgs that had caught
up, and checkToolchain compared 1.27.1 against itself.
Keeps the interlocked pins current and reports what it could not move.
Areas apply, gate and commit one at a time, so a dependency that breaks
the build costs one commit rather than the whole pull request.
Kristoffer Dalby