[3.15] gh-154467: Fix empty (Pdb) prompt when attaching to a process with pdb -p (GH-154469) - #156397
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…ith pdb -p (pythonGH-154469) _PdbServer inherits _cmdloop, which wraps cmdloop() in _maybe_use_pyrepl_as_stdin(). That context manager blanks self.prompt to '' so that a local pyrepl draws the prompt itself. The remote server, however, never reads from a local pyrepl -- it transmits self.prompt to the client over the socket -- so the blanking made it send an empty prompt whenever the target process had a pyrepl-capable terminal (pyrepl_input is set). Override _maybe_use_pyrepl_as_stdin() in _PdbServer to a no-op, keeping the real prompt. Add an integration test that attaches to a target running under a pty, so PyREPL is genuinely enabled inside it, and asserts the transmitted prompt is "(Pdb) ". (cherry picked from commit 1ec5607) Co-authored-by: Łukasz Langa <lukasz@langa.pl> Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This was referenced Aug 26, 2026
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_PdbServer inherits _cmdloop, which wraps cmdloop() in
_maybe_use_pyrepl_as_stdin(). That context manager blanks self.prompt to ''
so that a local pyrepl draws the prompt itself. The remote server, however,
never reads from a local pyrepl -- it transmits self.prompt to the client
over the socket -- so the blanking made it send an empty prompt whenever the
target process had a pyrepl-capable terminal (pyrepl_input is set).
Override _maybe_use_pyrepl_as_stdin() in _PdbServer to a no-op, keeping the
real prompt. Add an integration test that attaches to a target running under
a pty, so PyREPL is genuinely enabled inside it, and asserts the transmitted
prompt is "(Pdb) ".
(cherry picked from commit 1ec5607)
Co-authored-by: Łukasz Langa lukasz@langa.pl
Co-authored-by: Claude Opus 4.8 (1M context) noreply@anthropic.com
(Pdb)prompt #154467