e0b94741

By: Michael Lynch <git@mtlynch.io>

Isolate Go toolchain settings in Nix workflows

Ignore user Go settings in the dev shell so the pinned Nix Go toolchain remains authoritative. This prevents persisted user settings such as GOROOT from making the Go 1.25.5 binary invoke mismatched Go 1.26.1 tools and fail with:

compile: version "go1.26.1" does not match go tool version "go1.25.5"

Keep GOPATH isolated in the dev shell for project-specific installed tools and modules, but let Go use its default build cache. Simplify Nix build steps by relying on their temporary HOME and Go defaults instead of manually exporting GOPATH, GOCACHE, and GOMODCACHE. The go-tests setup now creates analyzer symlinks in the GOPATH reported by `go env`.

Testing:
- nix develop --command ./dev-scripts/serve
- nix build .#go-tests
- dev-scripts/git-hooks/pre-commit
- nix flake check

Timeline