diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go index c0c86ab9f5..6ce276537b 100644 --- a/src/cmd/go/go_test.go +++ b/src/cmd/go/go_test.go @@ -2848,3 +2848,35 @@ func TestExecInDeletedDir(t *testing.T) { // `go version` should not fail tg.run("version") } + +// A missing C compiler should not force the net package to be stale. +// Issue 47215. +func TestMissingCC(t *testing.T) { + if !canCgo { + t.Skip("test is only meaningful on systems with cgo") + } + cc := os.Getenv("CC") + if cc == "" { + cc = "gcc" + } + if filepath.IsAbs(cc) { + t.Skipf(`"CC" (%s) is an absolute path`, cc) + } + _, err := exec.LookPath(cc) + if err != nil { + t.Skipf(`"CC" (%s) not on PATH`, cc) + } + + tg := testgo(t) + defer tg.cleanup() + netStale, _ := tg.isStale("net") + if netStale { + t.Skip(`skipping test because "net" package is currently stale`) + } + + tg.setenv("PATH", "") // No C compiler on PATH. + netStale, _ = tg.isStale("net") + if netStale { + t.Error(`clearing "PATH" causes "net" to be stale`) + } +} diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go index b506b83656..5a225fb9f1 100644 --- a/src/cmd/go/internal/work/exec.go +++ b/src/cmd/go/internal/work/exec.go @@ -252,8 +252,15 @@ func (b *Builder) buildActionID(a *Action) cache.ActionID { ccExe := b.ccExe() fmt.Fprintf(h, "CC=%q %q %q %q\n", ccExe, cppflags, cflags, ldflags) - if ccID, err := b.gccToolID(ccExe[0], "c"); err == nil { - fmt.Fprintf(h, "CC ID=%q\n", ccID) + // Include the C compiler tool ID so that if the C + // compiler changes we rebuild the package. + // But don't do that for standard library packages like net, + // so that the prebuilt .a files from a Go binary install + // don't need to be rebuilt with the local compiler. + if !p.Standard { + if ccID, err := b.gccToolID(ccExe[0], "c"); err == nil { + fmt.Fprintf(h, "CC ID=%q\n", ccID) + } } if len(p.CXXFiles)+len(p.SwigCXXFiles) > 0 { cxxExe := b.cxxExe()