Handle missing PYTHONPATH in environment.

1 files changed, 1 insertions, 1 deletions

diff --git a/seivot b/seivot
index e518497..62b128d 100755
--- a/seivot
+++ b/seivot
@@ -164,7 +164,7 @@ class Obnam(BackupProgram):
             }
             env['OBNAM_PROFILE'] = self.settings['obnam-profile'] % namepattern
         if self._larch_branch:
-            old = env['PYTHONPATH']
+            old = env.get('PYTHONPATH')
             if old:
                 new = '%s:%s' % (self._larch_branch, old)
             else: