[tutorials][test] Specify the include path for SOFIE tutorials in CMake

We don't want to rely on environment variables like `ROOTSYS` in the
tutorials, and we should also not leak details of the test setup like
`$ROOTSYS/runtutorials` in the user-facing tutorials.

Author: guitargeek

tutorials/CMakeLists.txt

@@ -9,9 +9,25 @@ set(ROOT_root_CMD $<TARGET_FILE:root.exe>)
 set(pythonpaths ${localruntimedir} $ENV{PYTHONPATH})
 cmake_path(CONVERT "${pythonpaths}" TO_NATIVE_PATH_LIST pythonpaths_native)
 
-set(root_includepaths ${CMAKE_BINARY_DIR}/tutorials/io/tree ${DEFAULT_ROOT_INCLUDE_PATH})
+set(root_includepaths
+    ${CMAKE_BINARY_DIR}/tutorials/io/tree
+    # Some SOFIE tutorials include headers with code generated by other
+    # tutorials, which ends up in runtutorials/
+    ${CMAKE_BINARY_DIR}/runtutorials
+    ${DEFAULT_ROOT_INCLUDE_PATH}
+)
 cmake_path(CONVERT "${root_includepaths}" TO_NATIVE_PATH_LIST root_includepaths_native)
 
+# The environment argument gets serialized in ROOT_ADD_TEST for the
+# RootTestDriver, and then deserialized in the latter with multiple steps of
+# string parsing. We have to escape the semicolon excessively, because in every
+# parsing step we lose one semicolon. Also we use the SEMICOLON generator
+# expression, so at least we don't have to worry about escaping for the initial
+# configuration stage.
+# TODO: consider improving ROOT_ADD_TEST and RootTestDriver.cmake so this is not necessary.
+string(REPLACE ";" "\\\\\\\\$<SEMICOLON>" pythonpaths_escaped "${pythonpaths_native}")
+string(REPLACE ";" "\\\\\\\\$<SEMICOLON>" root_includepaths_escaped "${root_includepaths_native}")
+
 # - Set the environment for the tutorials, which also contains some environment
 # variables related to limiting the number of threads used by NumPy and
 # enabling batch mode.
@@ -22,9 +38,9 @@ set(TUTORIAL_ENV
     MPLBACKEND=AGG
     OMP_NUM_THREADS=1
     OPENBLAS_NUM_THREADS=1
-    PYTHONPATH=${pythonpaths_native}
+    PYTHONPATH=${pythonpaths_escaped}
     ROOT_BATCH=1
-    ROOT_INCLUDE_PATH=${root_includepaths_native}
+    ROOT_INCLUDE_PATH=${root_includepaths_escaped}
 )
 
 #---Copy the CTestCustom.cmake file into the build directory--------

tutorials/machine_learning/TMVA_SOFIE_GNN_Application.C

@@ -8,7 +8,6 @@
 // need to add include path to find generated model file
 #ifdef __CLING__
 R__ADD_INCLUDE_PATH($PWD)
-R__ADD_INCLUDE_PATH($ROOTSYS/runtutorials)
 #endif
 
 #include "encoder.hxx"

tutorials/machine_learning/TMVA_SOFIE_RDataFrame.C

@@ -25,7 +25,6 @@ using namespace TMVA::Experimental;
 // need to add the current directory (from where we are running this macro)
 // to the include path for Cling
 R__ADD_INCLUDE_PATH($PWD)
-R__ADD_INCLUDE_PATH($ROOTSYS/runtutorials)
 #include "Higgs_trained_model.hxx"
 #include "TMVA/SOFIEHelpers.hxx"