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:

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