Use `${PYTHON_EXECUTABLE}` instead of `py` in cmake (#7042)

* Emit include for bfbs-gen-embed

* Use python3 explicitly

* bump min python version to 3.6

* Sort find_package for python

* try casting Path to string

* cast WindowsPath to string to please CI

* stringify the wrong thing

* another stringify path

2 files changed, 9 insertions, 9 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1a7ceaaa..b4a489f2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -526,16 +526,16 @@ function(compile_flatbuffers_schema_to_embedded_binary SRC_FBS OPT)
   register_generated_output(${GEN_BFBS_HEADER})
 endfunction()
 
-# Look if we have python 3 installed so that we can run the generate code python
-# script after flatc is built.
-find_package(PythonInterp 3)
+# Look if we have python 3.5 installed so that we can run the generate code
+# python script after flatc is built.
+find_package(PythonInterp 3.5)
 
 if(PYTHONINTERP_FOUND AND
   # Skip doing this if the MSVC version is below VS 12.
   # https://cmake.org/cmake/help/latest/variable/MSVC_VERSION.html
   (NOT MSVC OR MSVC_VERSION GREATER 1800))
   if(MSVC)
-    set(GENERATION_SCRIPT py scripts/generate_code.py) 
+    set(GENERATION_SCRIPT ${PYTHON_EXECUTABLE} scripts/generate_code.py) 
    else()
     set(GENERATION_SCRIPT scripts/generate_code.py)
   endif()
diff --git a/scripts/generate_code.py b/scripts/generate_code.py
index 39b82856..7902f0ed 100755
--- a/scripts/generate_code.py
+++ b/scripts/generate_code.py
@@ -74,7 +74,7 @@ def flatc(
     cmd += [schema] if isinstance(schema, str) else schema
     if data:
         cmd += [data] if isinstance(data, str) else data
-    result = subprocess.run(cmd, cwd=cwd, check=True)
+    result = subprocess.run(cmd, cwd=str(cwd), check=True)
 
 
 # Glob a pattern relative to file path
@@ -360,7 +360,7 @@ assert (
     new_monster_file.exists()
 ), "filename suffix option did not produce a file"
 assert filecmp.cmp(
-    orig_monster_file, new_monster_file
+    str(orig_monster_file), str(new_monster_file)
 ), "filename suffix option did not produce identical results"
 new_monster_file.unlink()
 
@@ -409,6 +409,6 @@ new_reflection_file = Path(reflection_path, temp_dir, "reflection_generated.h")
 original_reflection_file = Path(
     root_path, "include/flatbuffers/reflection_generated.h"
 )
-if not filecmp.cmp(new_reflection_file, original_reflection_file):
-    shutil.move(new_reflection_file, original_reflection_file)
-shutil.rmtree(Path(reflection_path, temp_dir))
+if not filecmp.cmp(str(new_reflection_file), str(original_reflection_file)):
+    shutil.move(str(new_reflection_file), str(original_reflection_file))
+shutil.rmtree(str(Path(reflection_path, temp_dir)))