fix virtualenv sysconfig prefix

debian/patches/deb-locations.diff

@@ -5,9 +5,9 @@ Subject: deb-locations
 ---
  Lib/distutils/command/install.py |  4 ++--
  Lib/pydoc.py                     |  4 ++++
- Lib/sysconfig.py                 | 47 +++++++++++++++++++++++++++++++++++-----
+ Lib/sysconfig.py                 | 46 +++++++++++++++++++++++++++++++++++-----
  Misc/python.man                  |  2 +-
- 4 files changed, 49 insertions(+), 8 deletions(-)
+ 4 files changed, 48 insertions(+), 8 deletions(-)
 
 diff --git a/Lib/distutils/command/install.py b/Lib/distutils/command/install.py
 index 01d5331..d25b82f 100644
@@ -45,10 +45,10 @@ index 4a8c10a..af16580 100755
 
  This can be overridden by setting the PYTHONDOCS environment variable
 diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
-index daf9f00..8a4e919 100644
+index daf9f00..908ea48 100644
 --- a/Lib/sysconfig.py
 +++ b/Lib/sysconfig.py
-@@ -56,6 +56,26 @@ _INSTALL_SCHEMES = {
+@@ -56,7 +56,28 @@ _INSTALL_SCHEMES = {
          'scripts': '{base}/Scripts',
          'data': '{base}',
          },
@@ -73,9 +73,11 @@ index daf9f00..8a4e919 100644
 +        'data': '{base}',
 +        },
      }
++_INSTALL_SCHEMES['venv'] = _INSTALL_SCHEMES['posix_prefix']
 
 
-@@ -237,11 +257,28 @@ def _get_preferred_schemes():
+ # NOTE: site.py has copy of this function.
+@@ -237,11 +258,26 @@ def _get_preferred_schemes():
              'home': 'posix_home',
              'user': 'osx_framework_user',
          }
@@ -84,28 +86,26 @@ index daf9f00..8a4e919 100644
 -        'home': 'posix_home',
 -        'user': 'posix_user',
 -    }
-+    if 'real_prefix' in sys.__dict__ or 'VIRTUAL_ENV' in os.environ:
-+        # virtual environments
++    # virtual environments
++    if hasattr(sys, 'real_prefix') or sys.base_prefix != sys.prefix:
 +        return {
-+            'prefix': 'posix_prefix',
++            'prefix': 'venv',
++            'home': 'posix_home',
++            'user': 'posix_user',
++        }
++    # default to /usr for package builds, /usr/local otherwise
++    elif os.environ.get('DEB_PYTHON_INSTALL_LAYOUT') in ('deb', 'deb_system'):
++        return {
++            'prefix': 'deb_system',
 +            'home': 'posix_home',
 +            'user': 'posix_user',
 +        }
 +    else:
-+        # default to /usr for package builds, /usr/local otherwise
-+        deb_build = os.environ.get('DEB_PYTHON_INSTALL_LAYOUT', 'posix_local')
-+        if deb_build in ('deb', 'deb_system'):
-+            return {
-+                'prefix': 'deb_system',
-+                'home': 'posix_home',
-+                'user': 'posix_user',
-+            }
-+        else:
-+            return {
-+                'prefix': 'posix_local',
-+                'home': 'posix_home',
-+                'user': 'posix_user',
-+            }
++        return {
++            'prefix': 'posix_local',
++            'home': 'posix_home',
++            'user': 'posix_user',
++        }
 
 
  def get_preferred_scheme(key):

debian/patches/multiarch.diff

@@ -23,10 +23,10 @@ index 6f086be..da46770 100644
      elif os.name == "nt":
          if python_build:
 diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
-index 8a4e919..2a22492 100644
+index 908ea48..2fc8cbe 100644
 --- a/Lib/sysconfig.py
 +++ b/Lib/sysconfig.py
-@@ -660,6 +660,12 @@ def get_config_vars(*args):
+@@ -659,6 +659,12 @@ def get_config_vars(*args):
              # the init-function.
              _CONFIG_VARS['userbase'] = _getuserbase()