josephsnyder/Slicer — comment on commit 3a6e1ccde5e17d1429271222204f9d7e6e5bff52
File: Modules/Loadable/TractographyDisplay/CMakeLists.txt line 8
By finetjul:

add MRML as the first subdirectory. Order is important, Logic and Widgets wouldn't be able to access the MRML cmake variables from a clean build.
Btw, it would be great if you delete the the inner build (directory Slicer-superbuild/Slicer-build) and build it again ( to make sure it works)