scripts: sphinx-pre-install: Make it compatible with Python 3.6

The minimal version requirements we have is 3.9. Yet, the
script which detects it is this one. So, let's try supporting
an old version here, as we may want to suggest to upgrade
Python version to build the docs.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/39d6e27a047bc3cc8208ac5e11fe6ba44faff9c4.1754992972.git.mchehab+huawei@kernel.org

diff --git a/scripts/sphinx-pre-install.py b/scripts/sphinx-pre-install.py
index dcee2181b72fb4405c60f02d8757ca8359fd3dbe..71d86b230b22b23bc52e0389652361e936be7403 100755 (executable)
--- a/scripts/sphinx-pre-install.py
+++ b/scripts/sphinx-pre-install.py
@@ -115,7 +115,8 @@ class SphinxDependencyChecker:
     def find_python_no_venv():
         # FIXME: does it makes sense now that this script is in Python?
 
-        result = subprocess.run(["pwd"], capture_output=True, text=True)
+        result = SphinxDependencyChecker.run(["pwd"], capture_output=True,
+                                             text=True)
         cur_dir = result.stdout.strip()
 
         python_names = ["python3", "python"]
@@ -135,12 +136,23 @@ class SphinxDependencyChecker:
     def run(*args, **kwargs):
         """Excecute a command, hiding its output by default"""
 
-        if not kwargs.get('capture_output', False):
+        capture_output = kwargs.pop('capture_output', False)
+
+        if capture_output:
+            if 'stdout' not in kwargs:
+                kwargs['stdout'] = subprocess.PIPE
+            if 'stderr' not in kwargs:
+                kwargs['stderr'] = subprocess.PIPE
+        else:
             if 'stdout' not in kwargs:
                 kwargs['stdout'] = subprocess.DEVNULL
             if 'stderr' not in kwargs:
                 kwargs['stderr'] = subprocess.DEVNULL
 
+        # Don't break with older Python versions
+        if 'text' in kwargs and sys.version_info < (3, 7):
+            kwargs['universal_newlines'] = kwargs.pop('text')
+
         return subprocess.run(*args, **kwargs)
 
     #