skip conda install cil if unneeded

Dockerfile

@@ -111,7 +111,7 @@ COPY --from=build --link --chown=${NB_USER} /opt/SIRF-SuperBuild/INSTALL/ /opt/S
 
 # install {SIRF-Exercises,CIL-Demos}
 COPY docker/user_demos.sh /opt/scripts/
-RUN BUILD_CIL="${BUILD_CIL}" bash /opt/scripts/user_demos.sh \
+RUN bash /opt/scripts/user_demos.sh \
  && fix-permissions /opt/SIRF-Exercises /opt/CIL-Demos "${CONDA_DIR}" /home/${NB_USER}
 
 # docker-stacks notebook

docker/user_demos.sh

@@ -22,8 +22,8 @@ if [ "$PYTHON" = "miniconda" ]; then
       # delete GPU deps
       sed -r -e '/^\s*- (astra-toolbox|tigre).*/d' -e '/^\s*- \S+.*#.*GPU/d' environment.yml > environment-sirf.yml
     fi
-    # do not install CIL from conda if BUILD_CIL is set
-    if test "${BUILD_CIL:-0}" != 0; then
+    # do not install CIL from conda if SuperBuild already built it
+    if test "$(conda list '^cil$')" != "[]"; then
       # delete CIL package from the environment file
       sed -r -i -e '/^\s*- (cil).*/d' environment-sirf.yml
     fi