Debugging Python with gdb
Here’s a quick reference for getting set up to debug Python with
at Debian and Ubuntu users.
Although I’d love to make this a full-fledged write up, it’s going to have to be a note to my future self for now.
It assumes you have
Get all of the things we need for Python debugging:
sudo apt-get install python2.7-dbg python2.7-dev gdb
Make sure we use Python with debugging symbols:
mkvirtualenv -p python2.7-dbg $PROJECT-dbg
Install dependencies with their debugging symbols:
pip install --no-binary :all: --global-option build --global-option debug -e .
Make Python GDB extensions available in virtualenv:
ln -s /usr/lib/debug/usr/bin/python2.7-gdb.py ~/.virtualenvs/$PROJECT-dbg/bin`
Once that’s set up, a handy thing is to run tests in gdb over and over again until they segfault:
gdb -ex r --args python ~/.virtualenvs/$PROJECT-dbg/bin/trial -u testcase
You might see errors about C files that can’t be found. Pay them no mind. If you had the libc6 source code in the right location, they would go away, and you’d learn very little about your Python program.
I have literally no idea how Ubuntu handles core dumps by default. Here’s what I ended up doing:
$ ulimit -c unlimited
$ echo "core" > c/proc/sys/kernel/core_pattern
This means core will be dumped in the current working directory.
Note: if you are using
trial, the coredump will be in
Note: for it to be any use at all, you have to have a coredump from a debugging build of Python.
- Debugging with GDB on the Python wiki
- How to use GDB Python debugging extension inside virtualenv on StackOverflow