ReleaseKit/docs/internal/gotool.md

Go command environments

internal/gotool resolves effective Go settings once for a validation or build operation and applies the shared environment to its Go commands. It uses internal/process for cancellation, the working directory, output, and wrapped errors.

Configuration discovery

The owner asks the installed go command for GOHOSTOS and GOHOSTARCH, then queries effective operational settings with that host selected. Both queries use GOTOOLCHAIN=local and controlled GOFLAGS. Discovery sets GOEXPERIMENT=none and clears architecture feature variables so an invalid or nonbaseline tuning value cannot prevent settings from being read. The experiment override is discovery-only.

The persistent Go environment remains active during discovery. The owner copies the effective cache and module-cache locations, Go root, temporary directory, and native cgo/C-tool configuration into its settings. This captures values supplied by either the process environment or the persistent Go environment file.

Configuration discovery parses JSON from stdout. Stderr is captured separately and included in command-failure diagnostics, so a successful query can emit warnings while supplying valid configuration.

Command environments

Every Go command receives GOENV=off, so removed persistent values cannot return. ReleaseKit owns GOFLAGS=-mod=readonly, GOWORK=off, GOTOOLCHAIN=local, GOPROXY=off, GONOPROXY=none, and GOSUMDB=off. Native commands use GOHOSTOS and GOHOSTARCH and retain the effective CGO_ENABLED, CC, CXX, PKG_CONFIG, and CGO_CFLAGS, CGO_CPPFLAGS, CGO_CXXFLAGS, and CGO_LDFLAGS. Static commands use the selected target and CGO_ENABLED=0.

Both modes clear GOEXPERIMENT and the Go architecture feature variables GOAMD64, GOARM, GOARM64, GO386, GOMIPS, GOMIPS64, GOPPC64, GORISCV64, and GOWASM. The selected Go toolchain supplies its ordinary baseline values. Effective GOCACHE, GOCACHEPROG, GOMODCACHE, GOPATH, GOROOT, and GOTMPDIR values are retained. Other process variables remain available to child commands.

Candidate validation uses native mode for the offline go test suite and selected full go vet pass. Package-compilation checks use static mode for each selected target and direct Go's output to the operating system null device, so they leave no binary artifact. Artifact builds also use static mode for selected-target compilation, then build the native version-check executable; that executable runs as a normal child process.