I’ve built Slicer and then SlicerRT from source several times in the past. I followed the online instructions.
In the same computer, I recently updated (via git pull) the Slicer and SlicerRT repositories to master, and then rebuilt from scratch.
The build of Slicer works fine, and I can start Slicer-build/Slicer without problems. The GUI shows perfectly fine, both directly within the computer as well as via ssh -X.
If I call directly /home/user/builds/build-Slicer_src-Desktop-Debug/Slicer-build/bin/SlicerApp-real that works fine, too.
The build of SlicerRt works fine, however, when I now start inner-build/SlicerWithSlicerRT, (no difference if locally or via ssh -X), I get the following error:
Note that GLX works fine, glxinfo and glxgears show the right output.
Could you let me know what can I do to debug this issue? Is there a way to get more verbose erro information? Some logfile to check? Any idea why this is happening?
If I run /home/user/builds/build-Slicer_src-Desktop-Debug/Slicer-build/bin/./SlicerApp-real --additional-module-paths /opt/SlicerRT_bld/inner-build/lib/Slicer-5.9/qt-scripted-modules /opt/SlicerRT_bld/inner-build/lib/Slicer-5.9/qt-loadable-modules /opt/SlicerRT_bld/inner-build/lib/Slicer-5.9/cli-modules --no-splash --verbose-module-discovery
the GUI pops up, but with some warnings:
File "<string>", line 5, in <module>
File "<string>", line 5, in <module>
ModuleNotFoundError: No module named 'ctk'
Traceback (most recent call last):
File "<string>", line 1, in <module>
NameError: name 'getSlicerRCFileName' is not defined
Traceback (most recent call last):
File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'slicer'
Traceback (most recent call last):
File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'slicer'
qSlicerScriptedLoadableModuleFactory - Failed to import module "NA" python extensions
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "<frozen importlib._bootstrap_external>", line 999, in exec_module
File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
File "/home/user/builds/build-Slicer_src-Desktop-Debug/Slicer-build/lib/Slicer-5.9/qt-scripted-modules/AddManyMarkupsFiducialTest.py", line 3, in <module>
import ctk
....
Loading module "ExternalBeamPlanning"
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/opt/SlicerRT_bld/inner-build/lib/Slicer-5.9/qt-scripted-modules/DoseEngines/__init__.py", line 1, in <module>
from .AbstractScriptedDoseEngine import *
File "/opt/SlicerRT_bld/inner-build/lib/Slicer-5.9/qt-scripted-modules/DoseEngines/AbstractScriptedDoseEngine.py", line 2, in <module>
import vtk, qt, ctk, slicer, logging
ModuleNotFoundError: No module named 'vtk'
....
and DICOM import and many other things are not working.
SlicerRT currently has known build errors with latest Slicer main. See SlicerPreview - Build Errors. So you may actually want to try latest Slicer Stable 5.8.1 if you are trying to find a configuration that can build SlicerRT successfully. See SlicerStable.
I’m having that on Arch Linux too, plus other encoding error messages; I’m using this brute force hack:
diff --git a/Base/Python/slicer/__init__.py b/Base/Python/slicer/__init__.py
index 1443f9b7f8..fbcb831339 100644
--- a/Base/Python/slicer/__init__.py
+++ b/Base/Python/slicer/__init__.py
@@ -183,6 +183,11 @@ except ImportError as detail:
import os
import sys
+import locale
+
+# 'ANSI_X3.4-1968' codec is being enforced since july 2025.
+# Dumb but needed. Don't use getlocale(). A literal is good also.
+locale.setlocale(locale.LC_ALL, locale.getdefaultlocale())
standalone_python = "python" in str.lower(os.path.split(sys.executable)[-1])
If you don’t want to patch the Slicer source tree, you may update __init__.py in your installed tree:
With this hack, Slicer starts but files are badly read (NRRD, DICOM…).
This fix yields a functional Slicer:
locale.setlocale(locale.LC_ALL, "C.UTF-8")
NOTE: this is just a temporary hack for my Linux build at the moment. It should not be needed at all and things should bet back to normal when the library/toolkit/infrastructure upgrade phase is over.
I just came back from vacation. I’m planning on working on SlicerRT related stuff later this week, at least fixing the build error. Please note that I’ll not be able to address Mac specific stuff, but hopefully it won’t come up.
Can you give me more information on how to reproduce the crash when entering the EBP module? Thanks!
Thanks! It may be due to loading the dependencies (especially IECTransformLogic). I have seen this, but since there is no working debug build for Slicer I cannot debug it currently.