diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index 2145ffb275..08b3cd0e6a 100644
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -3820,6 +3820,7 @@ func TestGoEnv(t *testing.T) {
 	tg := testgo(t)
 	tg.parallel()
 	defer tg.cleanup()
+	tg.setenv("GOOS", "freebsd") // to avoid invalid pair errors
 	tg.setenv("GOARCH", "arm")
 	tg.run("env", "GOARCH")
 	tg.grepStdout("^arm$", "GOARCH not honored")
@@ -4589,3 +4590,12 @@ func TestParallelNumber(t *testing.T) {
 		})
 	}
 }
+
+func TestWrongGOOSErrorBeforeLoadError(t *testing.T) {
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.setenv("GOPATH", filepath.Join(tg.pwd(), "testdata"))
+	tg.setenv("GOOS", "windwos")
+	tg.runFail("build", "exclude")
+	tg.grepStderr("unsupported GOOS/GOARCH pair", "GOOS=windwos go build exclude did not report 'unsupported GOOS/GOARCH pair'")
+}
diff --git a/src/cmd/go/internal/work/build.go b/src/cmd/go/internal/work/build.go
index 62ae7ef2bf..031c92e7f9 100644
--- a/src/cmd/go/internal/work/build.go
+++ b/src/cmd/go/internal/work/build.go
@@ -733,6 +733,17 @@ func (b *Builder) Init() {
 			base.AtExit(func() { os.RemoveAll(workdir) })
 		}
 	}
+
+	if _, ok := cfg.OSArchSupportsCgo[cfg.Goos+"/"+cfg.Goarch]; !ok && cfg.BuildContext.Compiler == "gc" {
+		fmt.Fprintf(os.Stderr, "cmd/go: unsupported GOOS/GOARCH pair %s/%s\n", cfg.Goos, cfg.Goarch)
+		os.Exit(2)
+	}
+	for _, tag := range cfg.BuildContext.BuildTags {
+		if strings.Contains(tag, ",") {
+			fmt.Fprintf(os.Stderr, "cmd/go: -tags space-separated list contains comma\n")
+			os.Exit(2)
+		}
+	}
 }
 
 // readpkglist returns the list of packages that were built into the shared library
@@ -1104,17 +1115,6 @@ func allArchiveActions(root *Action) []*Action {
 
 // do runs the action graph rooted at root.
 func (b *Builder) Do(root *Action) {
-	if _, ok := cfg.OSArchSupportsCgo[cfg.Goos+"/"+cfg.Goarch]; !ok && cfg.BuildContext.Compiler == "gc" {
-		fmt.Fprintf(os.Stderr, "cmd/go: unsupported GOOS/GOARCH pair %s/%s\n", cfg.Goos, cfg.Goarch)
-		os.Exit(2)
-	}
-	for _, tag := range cfg.BuildContext.BuildTags {
-		if strings.Contains(tag, ",") {
-			fmt.Fprintf(os.Stderr, "cmd/go: -tags space-separated list contains comma\n")
-			os.Exit(2)
-		}
-	}
-
 	// Build list of all actions, assigning depth-first post-order priority.
 	// The original implementation here was a true queue
 	// (using a channel) but it had the effect of getting