Fix the detection of unhappy installation paths under Windows

- External tools like VSCode can modify for example the case of the path saved in `sys.executable`
- As a general rule paths under Windows are case-insensitive

Author: Thierry RAMORASOAVINA

CHANGELOG.md

@@ -13,6 +13,7 @@
 
 ### Fixed
 - (`sklearn`) Default value of `n_features` for the supervised estimators
+- (`core`) Detection of an unhappy installation path in a venv under Windows
 
 ## 11.0.0.2 - 2026-01-26
 

khiops/core/internals/runner.py

@@ -1172,8 +1172,14 @@ def _detect_library_installation_incompatibilities(self, library_root_dir):
                 )
                 warning_list.append(warning)
 
+            os_dependent_library_root_dir = str(library_root_dir)
+            os_dependent_conda_prefix = os.environ["CONDA_PREFIX"]
+            if platform.system() == "Windows":
+                # warning : paths are case-insensitive under Windows
+                os_dependent_library_root_dir = os_dependent_library_root_dir.lower()
+                os_dependent_conda_prefix = os_dependent_conda_prefix.lower()
             # the conda environment must match the library installation
-            if not str(library_root_dir).startswith(os.environ["CONDA_PREFIX"]):
+            if not os_dependent_library_root_dir.startswith(os_dependent_conda_prefix):
                 error = (
                     f"Khiops Python library installation path '{library_root_dir}' "
                     "does not match the current Conda environment "
@@ -1184,9 +1190,13 @@ def _detect_library_installation_incompatibilities(self, library_root_dir):
                     "Go to https://khiops.org for instructions.\n"
                 )
                 error_list.append(error)
+            os_dependent_khiops_path = self.khiops_path
+            if platform.system() == "Windows":
+                # warning : paths are case-insensitive under Windows
+                os_dependent_khiops_path = os_dependent_khiops_path.lower()
             # the khiops executable path must also match the conda environment one
             # meaning khiops core was installed using conda
-            if not self.khiops_path.startswith(os.environ["CONDA_PREFIX"]):
+            if not os_dependent_khiops_path.startswith(os_dependent_conda_prefix):
                 error = (
                     f"Khiops binary path '{self.khiops_path}' "
                     "does not match the current Conda environment "
@@ -1226,11 +1236,17 @@ def _detect_library_installation_incompatibilities(self, library_root_dir):
             # no further check cannot be performed)
             base_dir = _infer_base_dir_for_conda_based_or_pip_installations()
             if len(base_dir) > 0:
+                os_dependent_base_prefix = sys.base_prefix
+                os_dependent_sys_prefix = sys.prefix
+                if platform.system() == "Windows":
+                    # warning : paths are case-insensitive under Windows
+                    os_dependent_base_prefix = os_dependent_base_prefix.lower()
+                    os_dependent_sys_prefix = os_dependent_sys_prefix.lower()
                 # within a virtual env, sys.prefix is set to the virtual env folder
                 # whereas sys.base_prefix remains unchanged.
                 # Please be aware that if a python executable of a virtual env is used
                 # the corresponding virtual env is activated and sys.prefix updated
-                if sys.base_prefix != sys.prefix:
+                if os_dependent_base_prefix != os_dependent_sys_prefix:
                     # the python executable location
                     # (within the virtual env or the conda-based env)
                     # must match the library installation
@@ -1240,11 +1256,15 @@ def _detect_library_installation_incompatibilities(self, library_root_dir):
                         # Under Windows, there are two cases :
                         (
                             # for conda-based installations python is inside 'base_dir'
-                            str(Path(sys.executable).parents[0]) != base_dir
+                            # warning : paths are case-insensitive under Windows
+                            str(Path(sys.executable.lower()).parents[0])
+                            != base_dir.lower()
                             and
                             # for 'binary+pip' installations (within a virtual env)
                             # python is inside 'base_dir'/Scripts
-                            str(Path(sys.executable).parents[1]) != base_dir
+                            # warning : paths are case-insensitive under Windows
+                            str(Path(sys.executable.lower()).parents[1])
+                            != base_dir.lower()
                         )
                         # Under Linux or MacOS a bin/ folder exists
                         or str(Path(sys.executable).parents[1]) != base_dir
@@ -1260,9 +1280,15 @@ def _detect_library_installation_incompatibilities(self, library_root_dir):
                         )
                         error_list.append(error)
                 else:
+                    os_dependent_sys_exec = sys.executable
+                    os_dependent_base_prefix = sys.base_prefix
+                    if platform.system() == "Windows":
+                        # warning : paths are case-insensitive under Windows
+                        os_dependent_sys_exec = os_dependent_sys_exec.lower()
+                        os_dependent_base_prefix = os_dependent_base_prefix.lower()
                     # the installation is not within a virtual env
                     # (sys.base_prefix == sys.prefix)
-                    if not sys.executable.startswith(sys.base_prefix):
+                    if not os_dependent_sys_exec.startswith(os_dependent_base_prefix):
                         # the executable is not the expected one
                         # (the system-wide python)
                         error = (
@@ -1281,9 +1307,19 @@ def _detect_library_installation_incompatibilities(self, library_root_dir):
                     # fetch the 'User site' site-packages path
                     # which is already adapted for each OS (Windows, MacOS, Linux)
                     user_site_packages_dir = site.getusersitepackages()
-                    if not str(library_root_dir).startswith(user_site_packages_dir):
+                    os_dependent_library_root_dir = str(library_root_dir)
+                    if platform.system() == "Windows":
+                        # warning : paths are case-insensitive under Windows
+                        os_dependent_library_root_dir = (
+                            os_dependent_library_root_dir.lower()
+                        )
+                    if not os_dependent_library_root_dir.startswith(
+                        user_site_packages_dir
+                    ):
                         # the library is not installed on the 'User site'
-                        if not str(library_root_dir).startswith(sys.base_prefix):
+                        if not os_dependent_library_root_dir.startswith(
+                            os_dependent_base_prefix
+                        ):
                             # the library is supposed to be installed system-wide,
                             # but it seems that the location is wrong
                             error = (