remove the error code from the error message.

Author: google-yfyang

system/lib/libc/musl/src/errno/strerror.c

@@ -36,9 +36,7 @@ char *__strerror_l(int e, locale_t loc)
 #endif
 #ifdef __EMSCRIPTEN__
 	if (e < 0 || e >= sizeof errmsgidx / sizeof *errmsgidx || (e != 0 && !errmsgidx[e])) {
-		static char buf[32];
-		snprintf(buf, sizeof buf, "Unknown error %d", e);
-		return buf;
+		return "Unknown error";
 	}
 	s = (char *)&errmsgstr + errmsgidx[e];
 	// strerror is a (debug) dependency of many emscripten syscalls which mean it

test/test_core.py

@@ -6169,10 +6169,6 @@ def test_unistd_curdir(self):
   def test_unistd_close(self):
     self.do_run_in_out_file_test('unistd/close.c')
 
-  @also_with_noderawfs
-  def test_unistd_errno(self):
-    self.do_run_in_out_file_test('unistd/errno.c')
-
   def test_unistd_fsync_stdout(self):
     self.do_run_in_out_file_test('unistd/fsync_stdout.c')
 

test/test_other.py

@@ -13124,6 +13124,9 @@ def test_wasmfs_before_preload(self):
   def test_hello_world_above_2gb(self):
     self.do_run_in_out_file_test('hello_world.c', cflags=['-sGLOBAL_BASE=2GB', '-sINITIAL_MEMORY=3GB'])
 
+  def test_unistd_strerror(self):
+    self.do_run_in_out_file_test('unistd/strerror.c')
+
   def test_hello_function(self):
     # hello_function.cpp is referenced/used in the docs.  This test ensures that it
     # at least compiles.

test/unistd/errno.out

@@ -1,17 +1,13 @@
 /*
- * Copyright 2011 The Emscripten Authors.  All rights reserved.
+ * Copyright 2025 The Emscripten Authors.  All rights reserved.
  * Emscripten is available under two separate licenses, the MIT license and the
  * University of Illinois/NCSA Open Source License.  Both these licenses can be
  * found in the LICENSE file.
  */
 
 #include <stdio.h>
 #include <string.h>
-#include <errno.h>
-#include <unistd.h>
-#include <emscripten.h>
 
 int main() {
-    int error = -1;
-    printf("errno: %s\n", strerror(error));
+    printf("errno: %s\n", strerror(-1));
 }

test/unistd/errno.c renamed to test/unistd/strerror.c

@@ -0,0 +1 @@
+errno: Unknown error