Bugjar¶
Bugjar is part of the `BeeWare suite`_. The project website is http://pybee.org/bugjar.
Anyone who learned to code in the mid to late 80s probably spent some time with a Borland compiler – probably either Turbo Pascal or Turbo C. One of the best features of the Turbo compilers was their IDE – and in particular, a really good visual debugger that would let you inspect code while it was running.
Then we all moved to Unix, and somehow forgot what a good debugger was. GDB is perfectly functional, but isn’t very intuitive. GDB gives you perfect control over the execution of your code, but bad contextual information to let you know what control you should be exercising.
Then came Python. Python’s execution model contains excellent debugging hooks, and supplies PDB as a proof of concept. PDB is an interface that shares many similarities with GDB – text mode, fantastic control, but very bad contextual information.
So - enter bugjar. A graphical interface for debugging code.
PDB, but with the context to help you step through code in a meaningful way.
Quickstart¶
Bugjar can be installed with pip:
$ pip install bugjar
You can then debug a Python script by typing the following at a shell prompt:
$ bugjar myscript.py arg1 arg2
This will start a graphical interface, with myscript.py loaded into the
source code window. You can set (or remove) breakpoints by clicking on line
numbers; you can step through and into code; or you can set the program
running unconstrained. Each time the debugger stops at a breakpoint, the
inspector will be updated with the current contents of locals, globals, and
builtins.
The Python script will run using your current environment; if you have an active virtualenv, that environment will be current.
When you quit the debugger, the script will be terminated.
Problems under Ubuntu¶
Ubuntu’s packaging of Python omits the idlelib library from it’s base
packge. If you’re using Python 2.7 on Ubuntu 13.04, you can install
idlelib by running:
$ sudo apt-get install idle-python2.7
For other versions of Python and Ubuntu, you’ll need to adjust this as appropriate.
Problems under Windows¶
If you’re running Cricket in a virtualenv, you’ll need to set an environment variable so that Cricket can find the TCL graphics library:
$ set TCL_LIBRARY=c:\Python27\tcl\tcl8.5
You’ll need to adjust the exact path to reflect your local Python install.
You may find it helpful to put this line in the activate.bat script
for your virtual environment so that it is automatically set whenever the
virtualenv is activated.
Documentation¶
Documentation for bugjar can be found on `Read The Docs`_.
Community¶
Bugjar is part of the `BeeWare suite`_. You can talk to the community through:
We foster a welcoming and respectful community as described in our BeeWare Community Code of Conduct.
Contents:
Headless mode¶
Bugjar can also operate in a headless mode. This can be used to debug processes running on a remote machine (although it also works on local machines).
In headless mode, Bugjar is split into two parts:
- The Net: a headless backend responsible for debugging code
- The Jar: the GUI used to inspect code.
To debug in headless mode, you first start a headless debugger (the net) on the process that you want to debug:
$ bugjar-net myscript.py arg1 arg2
Then, on the machine that you want to visualize the debugging session, you start the user interface (the jar), and attach it to the net:
$ bugjar-jar –host example.com
If the net and the jar are running on the same machine, the
--host example.com argument can be ommitted.
Unlike local mode, when you quit the debugger, the script will not be terminated by closing the jar. If you close the jar, and reopen a new session, the GUI will resume where it left off. The net is responsible for running the script; when the net is stopped, the script will be terminated.
Contributing to Bugjar¶
If you experience problems with bugjar, log them on GitHub. If you want to contribute code, please fork the code and submit a pull request.
Setting up your development environment¶
The recommended way of setting up your development envrionment for bugjar
is to install a virtual environment, install the required dependencies and
start coding. Assuming that you are using virtualenvwrapper, you only have
to run:
$ git clone git@github.com:pybee/bugjar.git
$ cd bugjar
$ mkvirtualenv bugjar
bugjar uses unittest (or unittest2 for Python < 2.7) for its own test
suite as well as additional helper modules for testing. To install all the
requirements for bugjar, you have to run the following commands within your
virutal envrionment:
$ pip install -e .
$ pip install -r requirements_dev.txt
In case you are running a python version < 2.7 please use the
requirements_dev_python2.7.txt instead because unittest2 is not part
of the standard library for these version.
Now you are ready to start hacking! Have fun!
Bugjar Roadmap¶
Bugjar is a new project - we have lots of things that we’d like to do. If you’d like to contribute, providing a patch for one of these features:
- Port to Python 3
- Add the ability to browse objects in the stack
- Add the ability to add user-defined expressions to watch.