diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go
index bbd73aa8be..cc5610acda 100644
--- a/src/cmd/compile/internal/noder/noder.go
+++ b/src/cmd/compile/internal/noder/noder.go
@@ -40,6 +40,7 @@ func LoadPackage(filenames []string) {
 		noders[i] = &p
 	}
 
+	// Move the entire syntax processing logic into a separate goroutine to avoid blocking on the "sem".
 	go func() {
 		for i, filename := range filenames {
 			filename := filename
diff --git a/test/fixedbugs/issue52127.go b/test/fixedbugs/issue52127.go
new file mode 100644
index 0000000000..7738c3fabf
--- /dev/null
+++ b/test/fixedbugs/issue52127.go
@@ -0,0 +1,62 @@
+// run
+//go:build !js
+// +build !js
+
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 52127: Too many syntax errors in many files can
+// cause deadlocks instead of displaying error messages
+// correctly.
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+func main() {
+	dir, err := os.MkdirTemp("", "issue52127")
+	if err != nil {
+		panic(err)
+	}
+	defer os.RemoveAll(dir)
+
+	args := []string{"go", "build"}
+	write := func(prefix string, i int, data string) {
+		filename := filepath.Join(dir, fmt.Sprintf("%s%d.go", prefix, i))
+		if err := os.WriteFile(filename, []byte(data), 0o644); err != nil {
+			panic(err)
+		}
+		args = append(args, filename)
+	}
+
+	for i := 0; i < 100; i++ {
+		write("a", i, `package p
+`)
+	}
+	for i := 0; i < 100; i++ {
+		write("b", i, `package p
+var
+var
+var
+var
+var
+`)
+	}
+
+	cmd := exec.Command(args[0], args[1:]...)
+	output, err := cmd.CombinedOutput()
+	if err == nil {
+		panic("compile succeeded unexpectedly")
+	}
+	if !bytes.Contains(output, []byte("syntax error:")) {
+		panic(fmt.Sprintf(`missing "syntax error" in compiler output; got: 
+%s`, output))
+	}
+}
\ No newline at end of file