{Name: "CGO_CPPFLAGS", Value: join(cppflags)},
		{Name: "CGO_CXXFLAGS", Value: join(cxxflags)},
		{Name: "CGO_FFLAGS", Value: join(fflags)},
		{Name: "CGO_LDFLAGS", Value: join(ldflags)},
		{Name: "PKG_CONFIG", Value: b.PkgconfigCmd()},
		{Name: "GOGCCFLAGS", Value: join(cmd[3:])},
	}

	for i := range ret {
		ev := &ret[i]
		switch ev.Name {
		case "GOGCCFLAGS": // GOGCCFLAGS cannot be modified
		case "CGO_CPPFLAGS":