[3.11] gh-114257: Ignore the FileNotFound error in ctypes.util._is_elf() (GH-114394) (GH-114445)

(cherry picked from commit 7fc51c3)

Co-authored-by: AN Long <aisk@users.noreply.github.com>

Author: miss-islington

Lib/ctypes/test/test_find.py

@@ -122,6 +122,9 @@ def test_find_library_with_ld(self):
              unittest.mock.patch("ctypes.util._findLib_gcc", lambda *args: None):
             self.assertNotEqual(find_library('c'), None)
 
+    def test_gh114257(self):
+        self.assertIsNone(find_library("libc"))
+
 
 if __name__ == "__main__":
     unittest.main()

Lib/ctypes/util.py

@@ -96,8 +96,11 @@ def find_library(name):
     def _is_elf(filename):
         "Return True if the given file is an ELF file"
         elf_header = b'\x7fELF'
-        with open(filename, 'br') as thefile:
-            return thefile.read(4) == elf_header
+        try:
+            with open(filename, 'br') as thefile:
+                return thefile.read(4) == elf_header
+        except FileNotFoundError:
+            return False
 
     def _findLib_gcc(name):
         # Run GCC's linker with the -t (aka --trace) option and examine the

Misc/NEWS.d/next/Library/2024-01-21-16-32-55.gh-issue-114257.bCFld5.rst

@@ -0,0 +1,2 @@
+Dismiss the :exc:`FileNotFound` error in :func:`ctypes.util.find_library` and
+just return ``None`` on Linux.