Issue #25280: Import trace messages emitted in verbose (-v) mode are no

longer formatted twice.

Lib/importlib/_bootstrap_external.py

@@ -429,15 +429,15 @@ def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
     raw_size = data[8:12]
     if magic != MAGIC_NUMBER:
         message = 'bad magic number in {!r}: {!r}'.format(name, magic)
-        _bootstrap._verbose_message(message)
+        _bootstrap._verbose_message('{}', message)
         raise ImportError(message, **exc_details)
     elif len(raw_timestamp) != 4:
         message = 'reached EOF while reading timestamp in {!r}'.format(name)
-        _bootstrap._verbose_message(message)
+        _bootstrap._verbose_message('{}', message)
         raise EOFError(message)
     elif len(raw_size) != 4:
         message = 'reached EOF while reading size of source in {!r}'.format(name)
-        _bootstrap._verbose_message(message)
+        _bootstrap._verbose_message('{}', message)
         raise EOFError(message)
     if source_stats is not None:
         try:
@@ -447,7 +447,7 @@ def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
         else:
             if _r_long(raw_timestamp) != source_mtime:
                 message = 'bytecode is stale for {!r}'.format(name)
-                _bootstrap._verbose_message(message)
+                _bootstrap._verbose_message('{}', message)
                 raise ImportError(message, **exc_details)
         try:
             source_size = source_stats['size'] & 0xFFFFFFFF

Misc/NEWS

@@ -10,6 +10,9 @@ Release date: XXXX-XX-XX
 Core and Builtins
 -----------------
 
+- Issue #25280: Import trace messages emitted in verbose (-v) mode are no
+  longer formatted twice.
+
 - Issue #25227: Optimize ASCII and latin1 encoders with the ``surrogateescape``
   error handler: the encoders are now up to 3 times as fast. Initial patch
   written by Serhiy Storchaka.