Debugging

From FreeCAD Documentation
This page is a translated version of the page Debugging and the translation is 29% complete.

Prueba primero

Antes de pasar por la molestia de la depuración, utilice el Marco de pruebas para comprobar si las pruebas estándar funcionan correctamente. Si no se ejecutan por completo, es posible que haya una instalación defectuosa.

Línea de comandos

La depuración de FreeCAD está respaldada por algunos mecanismos internos. La versión de línea de comandos de FreeCAD proporciona algunas opciones para soporte de depuración.

Estas son las opciones reconocidas actualmente en FreeCAD 0.19:

Opciones genéricas:

  -v [ --version ]          Imprime la cadena de versión
  -h [ --help ]             Imprime el mensaje de ayuda
  -c [ --console ]          Comienza en modo consola
  --response-file arg       También se puede especificar con '@nombre'
  --dump-config             Configuración de volcados
  --get-config arg          Imprime el valor de la clave de configuración solicitada

Configuración:

  -l [ --write-log ]        Escribe un archivo de registro en:
                            $HOME/.local/share/FreeCAD/FreeCAD.log (Linux)
                            $HOME/Library/Application\ Support/FreeCAD/FreeCAD.log (macOS)
                            %APPDATA%\FreeCAD\FreeCAD.log 
  --log-file arg            A diferencia de --write-log, esto permite iniciar sesión en un 
                            archivo arbitrario
  -u [ --user-cfg ] arg     Archivo de configuración de usuario para cargar/guardar configuraciones de usuario
  -s [ --system-cfg ] arg   Archivo de configuración del sistema para cargar/guardar la configuración del sistema
  -t [ --run-test ] arg     Caso de prueba - o 0 para todos
  -M [ --module-path ] arg  Rutas de módulos adicionales
  -P [ --python-path ] arg  Rutas adicionales de Python
  --single-instance         Permite ejecutar una única instancia de la aplicación

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.

Para Linux

Depuración de Linux →

Requisitos previos:

  • paquete de software gdb instalado
  • una versión de depuración de FreeCAD (en este momento solo está disponible mediante la compilación desde el código fuente)
  • un modelo de FreeCAD que provoca un problema

Pasos: Ingrese lo siguiente en la ventana de su terminal:

Encuentre el binario FreeCAD en su sistema:

$ whereis freecad
freecad: /usr/local/freecad <--- for example

$ cd /usr/local/freecad/bin
$ gdb FreeCAD

GNUdebugger generará información de inicialización. El (gdb) muestra que GNUDebugger se está ejecutando en la terminal, ahora ingrese:

(gdb) handle SIG33 noprint nostop
(gdb) run

FreeCAD ahora se iniciará. Realice los pasos que hacen que FreeCAD se bloquee o se congele, luego ingrese en la ventana de terminal:

(gdb) bt

Esto generará una lista larga de exactamente lo que estaba haciendo el programa cuando falló o se congeló. Incluya esto con su informe de problemas.

(gdb) bt full

Imprima también los valores de las variables locales. Esto se puede combinar con un número para limitar la cantidad de fotogramas mostrados.

Para macOS

Depuración de macOS →

Requisitos previos:

  • software package lldb installed
  • a debug build of FreeCAD
  • a FreeCAD model that causes a crash

Steps: Enter the following in your terminal window:

$ cd FreeCAD/bin
$ lldb FreeCAD

LLDB will output some initializing information. The (lldb) shows the debugger is running in the terminal, now input:

(lldb) run

FreeCAD will now start up. Perform the steps that cause FreeCAD to crash or freeze, then enter in the terminal window:

(lldb) bt

This will generate a lengthy listing of exactly what the program was doing when it crashed or froze. Include this with your problem report.

List Libraries Loaded by FreeCAD

(Applicable to Linux and macOS)

Sometimes it's helpful to understand what libraries FreeCAD is loading, specifically if there are multiple libraries being loaded of the same name but different versions (version collision). In order to see which libraries are loaded by FreeCAD when it crashes you should open a terminal and run it in the debugger. In a second terminal window, find out the process id of FreeCAD:

ps -A | grep FreeCAD

Use the returned id and pass it to lsof:

lsof -p process_id

This prints a long list of loaded resources. So for example, if trying to ascertain if more than one Coin3d library versions is loaded, scroll through the list or search directly for Coin in the output:

lsof -p process_id | grep Coin

Python Debugging

For a more modern approach to debugging Python, see these posts:

winpdb

winpdb Debugging →

Here is an example of using Winpdb inside FreeCAD:

We need the Python debugger: Winpdb. If you do not have it installed, on Ubuntu/Debian install it with:

sudo apt-get install winpdb

Now lets setup the debugger.

  1. Start Winpdb.
  2. Set the debugger password to "test": Go to menu FilePassword" and set the password.

Now we will run a test Python script in FreeCAD step by step.

  1. Run winpdb and set the password (e.g. test)
  2. Create a Python file with this content
import rpdb2
rpdb2.start_embedded_debugger("test")
import FreeCAD
import Part
import Draft
print "hello"
print "hello"
import Draft
points=[FreeCAD.Vector(-3.0,-1.0,0.0),FreeCAD.Vector(-2.0,0.0,0.0)]
Draft.makeWire(points,closed=False,face=False,support=None)
  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 "<Input>" 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

Visual Studio Code (VS Code)

VS Code Debugging →

Prerequisites:

  • The ptvsd package needs to be installed in a Python 3 outside of FreeCAD, then the module must be copied to FreeCAD's Python library folder.
# In a cmd window that has a path to you local Python 3:
pip install ptvsd
# Then if your Python is installed in C:\Users\<userid>\AppData\Local\Programs\Python\Python37
# and your FreeCAD is installed in C:\freecad\bin
xcopy "C:\Users\<userid>\AppData\Local\Programs\Python\Python37\Lib\site-packages\ptvsd" "C:\freecad\bin\Lib\site-packages\ptvsd"

pypi page

Visual Studio Code documentation for remote debugging

Steps:

  • Add following code at the beginning of your script
import ptvsd
print("Waiting for debugger attach")
# 5678 is the default attach port in the VS Code debug configurations
ptvsd.enable_attach(address=('localhost', 5678), redirect_output=True)
ptvsd.wait_for_attach()
  • Add a debug configuration in Visual Studio Code Debug → Add Configurations….
  • The config should look like this:
    "configurations": [
        {
            "name": "Python: Attacher",
            "type": "python",
            "request": "attach",
            "port": 5678,
            "host": "localhost",
            "pathMappings": [
                {
                    "localRoot": "${workspaceFolder}",
                    "remoteRoot": "."
                }
            ]
        },
  • In VS Code add a breakpoint anywhere you want.
  • Launch the script in FreeCAD. FreeCAD freeze waiting for attachment.
  • In VS Code start debugging using created configuration. You should see variables in debugger area.
  • When setting breakpoints, VS Code will complain about not finding the .py file opened in the VS Code editor.
    • Change "remoteRoot": "." to "remoteRoot": "<directory of file>"
      • For example, if the Python file resides in /home/FC_myscripts/myscript.py
      • Change to: "remoteRoot": "/home/FC_myscripts"
    • If you're just debugging FreeCAD macros from the FreeCAD macro folder, and that folder is "C:/Users/<userid>/AppData/Roaming/FreeCAD/Macro", then use:
      • "localRoot": "C:/Users/<userid>/AppData/Roaming/FreeCAD/Macro",
      • "remoteRoot": "C:/Users/<userid>/AppData/Roaming/FreeCAD/Macro"
  • If your macro can't find ptvsd despite having installed it somewhere precede 'import ptvsd' with
from sys import path
sys.path.append('/path/to/site-packages')

Where the path is to the directory where ptvsd was installed.

  • On the left bottom edge of VSCode you can choose the Python executable - it's best to make this the version packaged with FreeCAD.

In the Mac package it is /Applications/FreeCAD.App/Contents/Resources/bin/python.

You can locate it on your system by typing

import sys
print(sys.executable)

into FreeCAD's Python console.

With LiClipse and AppImage

LiClipse Debugging →

  • Extract AppImage.
> ./your location/FreeCAD_xxx.AppImage --appimage-extract
> cd squashfs-root/
  • The sqashfs-root location is where the debugger later on is hooked up to.
  • Make sure you can start a FreeCAD session from within the squashfs-root location.
squashfs-root> ./usr/bin/freecadcmd
  • Should start up a FreeCAD commandline session.
  • Install LiClipse.
    • Comes ready with pydev and has installers for all platforms.
    • For linux it is just to extract (to any location) and run.
  • Configure liclipse for debugging.
    • Right-click pydev icon (upper right corner) and choose customize.
      • Activate "PyDev Debug" (through checkbox, or it might be needed to go to tab "Action Set Availability" and activate there first).
      • In the pydev menu you can now choose "start debug server".
    • Use menu window/open perspective/other > debug.
      • Right-click debug icon (upper right corner) and choose customize.
      • Checking "Debug" brings the debugging navigation tools to the toolbar.
    • Open preferences through menu window/preferences.
      • In PyDev/Interpreters add "new Interpreter by browsing".
      • The added interpreter should be: your loc/squashfs-root/usr/bin/python.
      • If you are only using this for fc, you can add AddOn workbench folders as well, or do that in a pydev-project later on.
  • Find path to pydevd.py in your liclipse installation.
    • Something along the lines of: your location/liclipse/plugins/org.python.pydev.xx/pysrc.
  • Create a regular pydev-project in liclipse.
    • Import external sources, for example a macro that you want to debug, or an external workbench.
    • In that macro (or workbench .py file) add the code lines:
import sys; sys.path.append("path ending with /pysrc")
import pydevd; pydevd.settrace()
  • This is where the execution will halt when the macro is run.
  • Start the liclipse debug server (menu pydev).
  • Start FreeCAD.
squashfs-root> ./usr/bin/freecad
  • Run the macro (or any other file with a pydevd.settrace() trigger) from within freecad, as you would normally do.
  • Happy debugging.
  • The use of LiClipse for remote debugging, and the steps described here related to liclipse, should work on any platform. The parts related to AppImage is for linux only.

Pyzo

See the main article about Pyzo.

Debugging OpenCasCade

For developers needing to dig deeper in to the OpenCasCade kernel, user @abdullah has created a thread orientation discussing how to do so.