The readline package doesn't return the errno for some errors in write_history, append_history, and history_truncate_file.
This caused an error in the CPython interpreter(at exit time) when the .python_history file was not writable.
In particular these calls return -1 when the internal histfile_restore call fails because rename fails. It's fine for histfile_restore to return the result from rename, but this should be checked for failure (e.g. -1) and handled appropriately by the caller in history_do_write and history_truncate_file. For example, in history_do_write they do the following:
if (rv == 0 && histname && tempname)
rv = histfile_restore (tempname, histname);
if (rv != 0)
{
if (tempname)
unlink (tempname);
history_lines_written_to_file = 0;
}
This needs a simple fix to update the value of rv when histfile_restore fails:
if (rv == 0 && histname && tempname)
rv = histfile_restore (tempname, histname);
if (rv != 0) {
rv = errno;
if (tempname)
unlink(tempname);
history_lines_written_to_file = 0;
}