Deciphering the output from the assertion, the stdout from gdb when running the test was:
--- BEGIN ---
Breakpoint 1, PyObject_Print (op=42, fp=0x401cf4e0, flags=1) at Objects/object.c:329
329     {
#3 Frame 0x81e322c, for file /home/mike/workspace/Python-2.7/Lib/test/gdb_sample.py, line 10, in baz (args=(1, 2, 3))
    print(42)
#7 (unable to read python frame information)
#10 Frame 0x81d5544, for file /home/mike/workspace/Python-2.7/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)
    baz(a, b, c)
#13 Frame 0x81d53dc, for file /home/mike/workspace/Python-2.7/Lib/test/gdb_sample.py, line 4, in foo (a=1, b=2, c=3)
    bar(a, b, c)
--- END ---

but the expected output was:

--- BEGIN ---
^.*
#[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \(a=1, b=2, c=3\)
    baz\(a, b, c\)
#[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \(a=1, b=2, c=3\)
    bar\(a, b, c\)
#[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \(\)
foo\(1, 2, 3\)
--- END  ---

There are various tests named "test_basic_command".  From the linenumber and assertion, it's clear that this one is PyBtTests.test_basic_command.

This looks a lot like issue 8482.

What compiler options did you use when building Python?