enhance CMakeMake easyblock to check whether correct Python installation was picked up by cmake

easybuild/easyblocks/generic/cmakemake.py

@@ -42,13 +42,13 @@
 from easybuild.framework.easyconfig import BUILD, CUSTOM
 from easybuild.tools.build_log import EasyBuildError, print_warning
 from easybuild.tools.config import build_option
-from easybuild.tools.filetools import change_dir, create_unused_dir, mkdir, which
+from easybuild.tools.filetools import change_dir, create_unused_dir, mkdir, read_file, which
 from easybuild.tools.environment import setvar
 from easybuild.tools.modules import get_software_root, get_software_version
 from easybuild.tools.run import run_cmd
 from easybuild.tools.systemtools import get_shared_lib_ext
 from easybuild.tools.utilities import nub
-
+import easybuild.tools.toolchain as toolchain
 
 DEFAULT_CONFIGURE_CMD = 'cmake'
 
@@ -317,9 +317,60 @@ def configure_step(self, srcdir=None, builddir=None):
                 self.cfg['configopts']])
 
         (out, _) = run_cmd(command, log_all=True, simple=False)
+        self.check_python_paths()
 
         return out
 
+    def check_python_paths(self):
+        """Check that there are no detected Python paths outside the EB installed PythonF"""
+        if not os.path.exists('CMakeCache.txt'):
+            self.log.warning("CMakeCache.txt not found. Python paths checks skipped.")
+            return
+        cmake_cache = read_file('CMakeCache.txt')
+        if not cmake_cache:
+            self.log.warning("CMake Cache could not be read. Python paths checks skipped.")
+            return
+
+        self.log.info("Checking Python paths")
+
+        python_paths = {
+            "executable": [],
+            "include_dir": [],
+            "library": [],
+        }
+        PYTHON_RE = re.compile(r"_?(?:Python|PYTHON)\d_(EXECUTABLE|INCLUDE_DIR|LIBRARY)[^=]*=(.*)")
+        for line in cmake_cache.splitlines():
+            match = PYTHON_RE.match(line)
+            if match:
+                path_type = match[1].lower()
+                path = match[2].strip()
+                self.log.info(f"Python {path_type} path: {path}")
+                python_paths[path_type].append(path)
+
+        ebrootpython_path = get_software_root("Python")
+        if not ebrootpython_path:
+            if any(python_paths.values()) and not self.toolchain.comp_family() == toolchain.SYSTEM:
+                self.log.warning("Found Python paths in CMake cache but Python is not a dependency")
+            # Can't do the check
+            return
+        ebrootpython_path = os.path.realpath(ebrootpython_path)
+
+        errors = []
+        for path_type, paths in python_paths.items():
+            for path in paths:
+                if path.endswith('-NOTFOUND'):
+                    continue
+                if not os.path.exists(path):
+                    errors.append(f"Python {path_type} does not exist: {path}")
+                elif not os.path.realpath(path).startswith(ebrootpython_path):
+                    errors.append(f"Python {path_type} path '{path}' is outside EBROOTPYTHON ({ebrootpython_path})")
+
+        if errors:
+            # Combine all errors into a single message
+            error_message = "\n".join(errors)
+            raise EasyBuildError(f"Python path errors:\n{error_message}")
+        self.log.info("Python check successful")
+
     def test_step(self):
         """CMake specific test setup"""
         # When using ctest for tests (default) then show verbose output if a test fails