test_gdb fails on 3k; some tests with a message "Error occurred in Python command: No frame is currently selected." A separate problem was reported as #8479; I'm attaching the full test_gdb output.
libpython.py had a type "PyStringObjectPtr" referencing "PyStringObject" type, whereas Python3 uses "PybytesObject". That's why you got this error. It should be fixed by r80311 (and r80312).
There was a patch for this attached to issue 8380, and you've fixed things in a different way. Should I regenerate a patch against what's now in SVN, or should we use my patch?
Victor's patch look fine to me (at least, I can't see a problem with it). If so, we should keep it. In any case, it does fix the problem reported here.
@Martin: What is your OS? In you wrote that you have gdb 7.0.1. Did you try to remove python-gdb.py? (test_gdb should remove and/or update this file!) I tested test_gdb of py3k on Debian Sid (gdb 7.1) and Ubuntu 9.10 (gdb 7.0): I got a lot of errors but I see the gdb backtrace, so the "No frame is currently selected" error is fixed. You should reopen the issue if it's not fixed on your host.