Extension tests failing due to missing LandmarkRegistration dependency

[jamesobutler]

Tests have been failing in the same way for SlicerRT since February 21st due to RegistrationLib being unable to be imported as this comes from LandmarkRegistration which was turned off completely in Slicer in https://github.com/Slicer/Slicer/commit/4daabe1342cdc01ebe516da96ee9547aac243156.

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Volumes/Dashboards/Preview/Slicer-0-build/python-install/lib/python3.6/imp.py", line 170, in load_source
    module = _exec(spec, sys.modules[name])
  File "<frozen importlib._bootstrap>", line 618, in _exec
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/Volumes/Dashboards/Preview/S-0-E-b/SlicerRT-build/inner-build/lib/Slicer-4.11/qt-scripted-modules/PlmRegister.py", line 4, in <module>
    import RegistrationLib
ModuleNotFoundError: No module named 'RegistrationLib'
loadSourceAsModule - Failed to load file "/Volumes/Dashboards/Preview/S-0-E-b/SlicerRT-build/inner-build/lib/Slicer-4.11/qt-scripted-modules/PlmRegister.py"  as module "PlmRegister" !
Fail to instantiate module  "PlmRegister"

[Sunderlandkyl]

Thanks for bringing this up! Do you know if anyone has taken on the task of updating the LandmarkRegistration module so that it can be re-enabled?

[jamesobutler]

Andras assigned https://github.com/Slicer/Slicer/issues/4764#event-3166405202 himself to a Slicer issue about updating LandmarkRegistration so that it could be enabled again in Slicer, but it doesn’t have the “in progress” status label so I don’t believe work has started yet.

[lassoan]

@Sunderlandkyl you are very familiar with Markups now. Could you take a stab on fixing the module?

I wanted to rework it a bit to make it more flexible, convenient, and robust - it would be nice to address some of these as well:

• allow placing landmarks separately, because right now if you place a landmark on an image then it automatically places it on the other, too, which is really bad if the two images are initially not aligned well
• do not force setting input volumes when entering the module: the popup annoys me a lot and prevents you from using the module for model-to-model, model-to-image, etc. segmentations
• markups are not associated with the parameter node robustly (it should use node references)

[Sunderlandkyl]

@lassoan sure, sounds good!

[jamesobutler]

LandmarkRegistration was added back into Slicer with https://github.com/Slicer/Slicer/commit/3987c758f59e5cc70b645d05d4db890e8b0202d1 so the tests aren't failing in this manner now.