--- a/hgext/convert/convcmd.py	Mon Jan 06 14:15:40 2025 -0500
+++ b/hgext/convert/convcmd.py	Sun Jan 05 21:03:17 2025 -0500
@@ -339,7 +339,7 @@
                     else:
                         m[child] = p1 + p2
         # if file does not exist or error reading, exit
-        except IOError:
+        except OSError:
             raise error.Abort(
                 _(b'splicemap file not found or error reading %s:') % path
             )