How to get python stacktraces in gdb on FreeBSD

gistfile1.sh

# First build the python package with DEBUG, and then install the resulting python-gdb.py script into a place where gdb will find it.

/usr/ports/lang/python27 # make config OPTIONS_FILE_SET=DEBUG
/usr/ports/lang/python27 # find . -name python-gdb.py
./work/Python-2.7.8/python-gdb.py
cp ./work/Python-2.7.8/python-gdb.py \
   /usr/local/bin/python2.7-gdb.py

# Now install gdb with python support:
/usr/ports/devel/gdb # make config OPTIONS_FILE_SET=PYTHON

# Then run your script:
gdb78 --args /usr/local/bin/python ~alfred/t.py
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Reading symbols from /usr/local/bin/python...done.
(gdb) run
Starting program: /usr/local/bin/python /home/alfred/t.py
^C[New Thread 802006400 (LWP 100848)]

Program received signal SIGINT, Interrupt.
[Switching to Thread 802006400 (LWP 100848)]
0x0000000800b886c2 in PyEval_EvalFrameEx (
    f=Frame 0x800806250, for file /home/alfred/t.py, line 4, in deep (x=28), 
    throwflag=0) at Python/ceval.c:1139
1139	            PUSH(x);
(gdb) py-bt
#0 Frame 0x800806250, for file /home/alfred/t.py, line 4, in deep (x=28)
    if x < 50:
#3 Frame 0x800806060, for file /home/alfred/t.py, line 5, in deep (x=27)
    deep(x+1)
#6 Frame 0x8007b3df0, for file /home/alfred/t.py, line 5, in deep (x=26)
    deep(x+1)
#9 Frame 0x8007b3c00, for file /home/alfred/t.py, line 5, in deep (x=25)
    deep(x+1)
#12 Frame 0x8007b3a10, for file /home/alfred/t.py, line 5, in deep (x=24)
    deep(x+1)
#15 Frame 0x8007b3820, for file /home/alfred/t.py, line 5, in deep (x=23)
    deep(x+1)