gistfile1.txt

diff --git a/lib/ansible/runner/__init__.py b/lib/ansible/runner/__init__.py
index 4d2bd66..76ce641 100644
--- a/lib/ansible/runner/__init__.py
+++ b/lib/ansible/runner/__init__.py
@@ -1223,7 +1223,11 @@ class Runner(object):
 
     def _remote_checksum(self, conn, tmp, path, inject):
         ''' takes a remote checksum and returns 1 if no file '''
-        python_interp = inject['hostvars'][inject['inventory_hostname']].get('ansible_python_interpreter', 'python')
+        import q ; q.q(repr(inject))
+        if inject['delegate_to']:
+            python_interp = inject['hostvars'][inject['delegate_to']].get('ansible_python_interpreter', python)
+        else:
+            python_interp = inject['hostvars'][inject['inventory_hostname']].get('ansible_python_interpreter', 'python')
         cmd = conn.shell.checksum(path, python_interp)
         data = self._low_level_exec_command(conn, cmd, tmp, sudoable=True)
         data2 = utils.last_non_blank_line(data['stdout'])

I had to make 2 minor changes to get it to work on my machine

diff --git a/lib/ansible/runner/__init__.py b/lib/ansible/runner/__init__.py
index 082dd44..5521a5c 100644
--- a/lib/ansible/runner/__init__.py
+++ b/lib/ansible/runner/__init__.py
@@ -1201,7 +1201,10 @@ class Runner(object):

     def _remote_checksum(self, conn, tmp, path, inject):
         ''' takes a remote checksum and returns 1 if no file '''
-        python_interp = inject['hostvars'][inject['inventory_hostname']].get('ansible_python_interpreter', 'python')
+        if inject['delegate_to']:
+            python_interp = inject['hostvars'][inject['delegate_to']].get('ansible_python_interpreter', 'python')
+        else:
+            python_interp = inject['hostvars'][inject['inventory_hostname']].get('ansible_python_interpreter', 'python')
         cmd = conn.shell.checksum(path, python_interp)
         data = self._low_level_exec_command(conn, cmd, tmp, sudoable=True)
         data2 = utils.last_non_blank_line(data['stdout'])