Debugging

Test first
Before you go through the pain of debugging use the test framework to check if the standard tests work properly. If not there is maybe a broken installation.

command line
The debugging of FreeCAD is supported by a few internal mechanisms. The command line version of FreeCAD provides to options for debugging support:
 * -v: With the "v" option FreeCAD gives a more verbose output.
 * -l: With the "l" option FreeCAD writes additional information to a logfile.

Generating a Backtrace
If you are running a version of FreeCAD from the bleeding edge of the development curve, it may "crash". You can help solve such problems by providing the developers with a "backtrace". To do this, you need to be running a "debug build" of the software. "Debug build" is a parameter that is set at compile time, so you'll either need to compile FreeCAD yourself, or obtain a pre-compiled "debug" version.

For Linux
Prerequisites:


 * software package gdb installed
 * a debug build of FreeCAD
 * a FreeCAD model that causes a crash

Steps: Enter the following in your terminal window: cd FreeCAD/bin gdb FreeCAD handle SIG33 noprint nostop run

FreeCAD will now start up. Perform the steps that cause FreeCAD to crash, then enter 'bt' in your terminal window. This will generate a lengthy listing of exactly what the program was doing when it crash. Include this with your problem report.

Python debugging
Here is an example of using winpdb inside FreeCAD:


 * 1) Run winpdb and set the password (e.g. test)
 * 2) Create a Python file with this content


 * 1) Start FreeCAD and load the above file into FreeCAD
 * 2) Press F6 to execute it
 * 3) Now FreeCAD will become unresponsive because the Python debugger is waiting
 * 4) Switch to the Windpdb GUI and click on "Attach". After a few seconds an item "" appears where you have to double-click
 * 5) Now the currently executed script appears in Winpdb.
 * 6) Set a break at the last line and press F5
 * 7) Now press F7 to step into the Python code of Draft.makeWire