To minimize what seems to be an increased risk of segfaults when using virtualenv with system packages, this commit introduces an alternative, which does away with the general system package availability, but adds symlinks to two svn related system packages when running checks.

- Legacy-Id: 12208

ietf/checks.py

@@ -1,7 +1,10 @@
 import os
+import sys
 import time
 from textwrap import dedent
 
+import debug                            # pyflakes:ignore
+
 from django.conf import settings
 from django.core import checks
 from django.utils.module_loading import import_string
@@ -213,6 +216,19 @@ def check_cache(app_configs, **kwargs):
 @checks.register('cache')
 def check_svn_import(app_configs, **kwargs):
     errors = []
+    # 
+    site_packages_dir = None
+    for p in sys.path:
+        if ('/env/' in p or '/venv/' in p) and '/site-packages' in p:
+            site_packages_dir = p
+            break
+    if site_packages_dir:
+        for path in settings.SVN_PACKAGES:
+            dir, name = os.path.split(path)
+            package_link = os.path.join(site_packages_dir, name)
+            if not os.path.exists(package_link):
+                os.symlink(path, package_link)
+    #
     if settings.SERVER_MODE == 'production':
         try:
             import svn                  # pyflakes:ignore
@@ -225,14 +241,15 @@ def check_svn_import(app_configs, **kwargs):
 
                     However, the subversion bindings seem to be unavailable.  The subversion
                     bindings are not available for install using pip, but must be supplied by
-                    the system package manager.  In order to be available within a python
-                    virtualenv, the virtualenv must have been created with the
-                    --system-site-packages flag, so that the packages installed by the system
-                    package manager are visible.
+                    the system package manager.  In order to be available within the python
+                    virtualenv, ietf.checks.check_svn_import() tries to create a symlink from
+                    the configured location of the system-provided svn package to the
+                    site-packages directory of the virtualenv. If you get this message, that has
+                    failed to provide the svn package.
 
                     Please install 'python-subversion' (Debian), 'subversion-python' (RedHat,
-                    CentOS, Fedora), 'subversion-python27bindings' (BSD); and set up a
-                    virtualenv using the --system-site-packages flag.  Further tips are
+                    CentOS, Fedora), 'subversion-python27bindings' (BSD); and provide the
+                    correct path to the svn package in settings.SVN_PACKAGE.  Further tips are
                     available at https://trac.edgewall.org/wiki/TracSubversion.
 
                     """).replace('\n', '\n   ').rstrip(),

ietf/settings.py

@@ -666,6 +666,10 @@ TRAC_WIKI_URL_PATTERN = "https://trac.ietf.org/trac/%s/wiki"
 TRAC_ISSUE_URL_PATTERN = "https://trac.ietf.org/trac/%s/report/1"
 TRAC_SVN_DIR_PATTERN = "/a/svn/group/%s"
 TRAC_SVN_URL_PATTERN = "https://svn.ietf.org/svn/group/%s/"
+SVN_PACKAGES = [
+    "/usr/lib/python2.7/dist-packages/svn",
+    "/usr/lib/python2.7/dist-packages/libsvn",
+]
 
 TRAC_ENV_OPTIONS = [
     ('project', 'name', "{name} Wiki"),