I close the issue. I cannot reproduce the issue on Fedora 32. Please open it if you can still reproduce it on the master branch. In this case, please mention your GDB version, Python version used by GDB and tested Python version.

* Python master at commit 9727694f08cad4b019d2939224e3416312b1c0e1
* gcc (GCC) 10.1.1 20200507 (Red Hat 10.1.1-1)
* GNU gdb (GDB) Fedora 9.1-5.fc32

On Fedora 32, GDB is linked to Python 3.8:

$ gdb 
GNU gdb (GDB) Fedora 9.1-5.fc32
(gdb) python import sys; print(sys.version)
3.8.3 (default, May 15 2020, 00:00:00) 
[GCC 10.1.1 20200507 (Red Hat 10.1.1-1)]


test_gdb:

vstinner@apu$ LC_ALL=C ./python -We -m test -vuall -m test_strings test_gdb
== CPython 3.10.0a0 (heads/master:9727694f08, Jun 11 2020, 15:44:14) [GCC 10.1.1 20200507 (Red Hat 10.1.1-1)]
== Linux-5.6.16-300.fc32.x86_64-x86_64-with-glibc2.31 little-endian
== cwd: /home/vstinner/python/master/build/test_python_151860
== CPU count: 8
== encodings: locale=UTF-8, FS=utf-8
0:00:00 load avg: 1.68 Run tests sequentially
0:00:00 load avg: 1.68 [1/1] test_gdb
GDB version 9.1:
    GNU gdb (GDB) Fedora 9.1-5.fc32
    Copyright (C) 2020 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.
test_strings (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of unicode strings ... ok

----------------------------------------------------------------------

Ran 1 test in 1.834s

OK

== Tests result: SUCCESS ==

1 test OK.

Total duration: 2.4 sec
Tests result: SUCCESS