drop install of gtk from CI steps (#248)

Signed-off-by: Jason Gorski <jasongorski@users.noreply.github.com>

.drone.yml

@@ -6,9 +6,9 @@ steps:
 - name: test
   image: pytorch/pytorch:1.2-cuda10.0-cudnn7-devel
   commands:
-  - apt-get update && apt-get -y install libgtk2.0-dev
-  - pip install --no-dependencies nuscenes-devkit opencv-python scikit-learn joblib pyquaternion cachetools
+  - pip install --no-dependencies nuscenes-devkit opencv-python-headless scikit-learn joblib pyquaternion cachetools
   - pip install -r requirements.txt
+  - apt-get update && apt-get -y install libglib2.0-0  # needed by opencv
   - flake8 --config=.flake8 .
   - python setup.py develop
   - . ./setenv.sh

.gitlab-ci.yml

@@ -2,9 +2,9 @@ image: "pytorch/pytorch:1.2-cuda10.0-cudnn7-devel"
 
 before_script:
   - pip install --upgrade pip>=18.0.0
-  - apt-get update && apt-get -y install libgtk2.0-dev
-  - pip install --no-dependencies nuscenes-devkit opencv-python scikit-learn joblib pyquaternion cachetools
+  - pip install --no-dependencies nuscenes-devkit opencv-python-headless scikit-learn joblib pyquaternion cachetools
   - pip install -r requirements.txt
+  - apt-get update && apt-get -y install libglib2.0-0  # needed by opencv
 
 stages:
   - build

kaolin/datasets/__init__.py

@@ -2,8 +2,15 @@
 from .modelnet import *
 from .shrec import *
 from .scannet import *
+
+# nuscenes-devkit will import matplotlib trying for an x11 backend, workaround here
+import matplotlib
+matplotlib.use('Agg')
+
 try:
     from .nusc import NuscDetection
 except ImportError as err:
     import_err = err
+    import traceback
     print("Warning: unable to import datasets/nusc:\n   %s" % import_err)
+    print("Warning: unable to import datasets/nusc:\n   %s" % traceback.print_exc())

setup.py

@@ -91,6 +91,11 @@ def KaolinCUDAExtension(*args, **kwargs):
 
 
 class KaolinBuildExtension(BuildExtension):
+    def __init__(self, *args, **kwargs):
+        kwargs = copy.deepcopy(kwargs)
+        kwargs['use_ninja'] = False  # ninja is interfering with compiling separate extensions in parallel
+        super().__init__(*args, **kwargs)
+
     def build_extensions(self):
         if not os.name == 'nt':
             FLAG_BLACKLIST = ['-Wstrict-prototypes']