More reliable way to get Blender's Python interpreter path (#70)

* More reliable way to get Python Blender interpreter path

* Test against latest versions in CI

* Blender 3.3.0 hangs download

* Comment job

Author: mondeja

.bumpversion.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 3.0.2
+current_version = 3.0.3
 
 [bumpversion:file:pytest_blender/__init__.py]
 

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
           # Test previous Blender versions
           - platform: ubuntu-latest
             pytest-version: '7.1.2'
-            blender-version: '2.83.9'
+            blender-version: '2.83.20'
             python-version: '3.8'
           - platform: ubuntu-latest
             pytest-version: '7.1.2'
@@ -41,8 +41,17 @@ jobs:
           # Test against Pytest v6
           - platform: ubuntu-latest
             pytest-version: '6.2.5'
-            blender-version: '2.93.8'
+            blender-version: '2.93.9'
             python-version: '3.9'
+          # Latest Blender (Py311)
+          #
+          # FIXME: Blender uses for 3.2.0 Python3.10,
+          # but the pytest-cov test fails because
+          # it does not show coverage:
+          #- platform: ubuntu-latest
+          #  pytest-version: '7.1.2'
+          #  blender-version: '3.2.0'
+          #  python-version: '3.11-dev'
           # Test in MacOS (Py310)
           - platform: macos-latest
             pytest-version: '7.1.2'

pytest_blender/__init__.py

@@ -1,4 +1,4 @@
-__version__ = "3.0.2"
+__version__ = "3.0.3"
 
 from pytest_blender.utils import (
     get_addons_dir,

pytest_blender/__main__.py

@@ -2,7 +2,11 @@
 import sys
 
 from pytest_blender import __version__
-from pytest_blender.utils import get_blender_binary_path_python, which_blender
+from pytest_blender.utils import (
+    GetPythonBlenderPathError,
+    get_blender_binary_path_python,
+    which_blender,
+)
 
 
 __description__ = "Show a Blender's builtin Python interpreter location."
@@ -44,10 +48,14 @@ def parse_args(args):
 
 def run(args):
     opts = parse_args(args)
-    blender_python = get_blender_binary_path_python(opts.blender_executable)
-    sys.stdout.write(f"{blender_python}\n")
-
-    return 0
+    try:
+        blender_python = get_blender_binary_path_python(opts.blender_executable)
+    except GetPythonBlenderPathError as exc:
+        sys.stderr.write(f"{exc.args[0]}\n")
+        return 1
+    else:
+        sys.stdout.write(f"{blender_python}\n")
+        return 0
 
 
 def main():

pytest_blender/utils.py

@@ -1,13 +1,25 @@
 import os
+import pprint
 import shutil
 import subprocess
 import sys
 import zipfile
 
 
+PYTEST_BLENDER_NEW_ISSUE_URL = (
+    "https://github.com/mondeja/pytest-blender/issues/new/choose"
+)
 ZIP_ROOTS_IGNORE = [".DStore", ".git", ".gitignore", "__pycache__"]
 
 
+class PytestBlenderException(Exception):
+    pass
+
+
+class GetPythonBlenderPathError(PytestBlenderException):
+    pass
+
+
 def zipify_addon_package(in_dirpath, out_dirpath):
     zipped_path = os.path.join(
         out_dirpath,
@@ -81,10 +93,11 @@ def get_blender_binary_path_python(blender_executable, blend_version=None):
     """
     if blend_version is None:
         blend_version = get_blender_version(blender_executable)
+    id_string = "BLENDER-PYTHON-PATH:"
     python_expr = (
-        "import sys;print(sys.executable);"
+        f"import sys;print('{id_string}',sys.executable);"
         if parse_version(blend_version) >= (2, 91)
-        else "import bpy;print(bpy.app.binary_path_python)"
+        else f"import bpy;print('{id_string}',bpy.app.binary_path_python)"
     )
 
     stdout = subprocess.check_output(
@@ -99,14 +112,20 @@ def get_blender_binary_path_python(blender_executable, blend_version=None):
 
     blender_python_path = None
     for line in stdout.decode("utf-8").splitlines():
-        # this should be enough to support Windows and Unix based systems
-        if (
-            os.path.exists(line)
-            and not os.path.isdir(line)
-            and "py" in os.path.basename(line.lower())
-        ):
-            blender_python_path = line
+        if line.startswith(id_string):
+            blender_python_path = line.split(" ", maxsplit=1)[1]
             break
+    if blender_python_path is None:
+        debugging_data = {
+            "platform": sys.platform,
+            "blender_executable": blender_executable,
+            "stdout": stdout,
+        }
+        raise GetPythonBlenderPathError(
+            "Failed to retrieve the Blender's Python interpreter path."
+            f" Please, submit a report at {PYTEST_BLENDER_NEW_ISSUE_URL}"
+            f" including the next data:\n{pprint.pformat(debugging_data)}"
+        )
     return blender_python_path
 
 

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = pytest_blender
-version = 3.0.2
+version = 3.0.3
 description = Blender Pytest plugin.
 long_description = file: README.md
 long_description_content_type = text/markdown