Update build.go

build.go

@@ -241,11 +241,20 @@ func verbosePrintf(message string, args ...interface{}) {
 	fmt.Printf("build: "+message, args...)
 }
 
-// cleanEnv returns a clean environment with GOPATH and GOBIN removed (if
-// present).
+// cleanEnv returns a clean environment with GOPATH, GOBIN and GO111MODULE
+// removed (if present).
 func cleanEnv() (env []string) {
+	removeKeys := map[string]struct{}{
+		"GOPATH":      struct{}{},
+		"GOBIN":       struct{}{},
+		"GO111MODULE": struct{}{},
+	}
+
 	for _, v := range os.Environ() {
-		if strings.HasPrefix(v, "GOPATH=") || strings.HasPrefix(v, "GOBIN=") {
+		data := strings.SplitN(v, "=", 2)
+		name := data[0]
+
+		if _, ok := removeKeys[name]; ok {
 			continue
 		}
 
@@ -554,7 +563,7 @@ func main() {
 		if !keepGopath {
 			verbosePrintf("remove %v\n", gopath)
 			if err = os.RemoveAll(gopath); err != nil {
-				die("remove GOPATH at %s failed: %v\n", err)
+				die("remove GOPATH at %s failed: %v\n", gopath, err)
 			}
 		} else {
 			verbosePrintf("leaving temporary GOPATH at %v\n", gopath)
@@ -599,7 +608,7 @@ func main() {
 	if runTests {
 		verbosePrintf("running tests\n")
 
-		err = test(cwd, gopath, config.Tests...)
+		err = test(filepath.Join(gopath, "src"), gopath, config.Tests...)
 		if err != nil {
 			die("running tests failed: %v\n", err)
 		}