# 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.

## 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. Builds
use static mode for selected-target compilation and the native version-check
build. The native version executable itself runs as a normal child process.