Pass __env__ to salt.modules.pip._get_cached_requirements

This fixes #6003, and resolves a traceback caused by the environment not
being passed to the function.

salt/modules/pip.py

@@ -26,32 +26,8 @@
 VALID_PROTOS = ['http', 'https', 'ftp']
 
 
-def _get_pip_bin(bin_env):
-    '''
-    Return the pip command to call, either from a virtualenv, an argument
-    passed in, or from the global modules options
-    '''
-    if not bin_env:
-        which_result = __salt__['cmd.which_bin'](['pip2', 'pip', 'pip-python'])
-        if which_result is None:
-            raise CommandNotFoundError('Could not find a `pip` binary')
-        return which_result
-
-    # try to get pip bin from env
-    if os.path.isdir(bin_env):
-        if salt.utils.is_windows():
-            pip_bin = os.path.join(bin_env, 'Scripts', 'pip.exe')
-        else:
-            pip_bin = os.path.join(bin_env, 'bin', 'pip')
-        if os.path.isfile(pip_bin):
-            return pip_bin
-        raise CommandNotFoundError('Could not find a `pip` binary')
-
-    return bin_env
-
-
-def _get_cached_requirements(requirements):
-    """Get the location of a cached requirements file; caching if necessary."""
+def _get_cached_requirements(requirements, __env__):
+    '''Get the location of a cached requirements file; caching if necessary.'''
     cached_requirements = __salt__['cp.is_cached'](
         requirements, __env__
     )
@@ -247,7 +223,8 @@ def install(pkgs=None,
     treq = None
     if requirements:
         if requirements.startswith('salt://'):
-            cached_requirements = _get_cached_requirements(requirements)
+            cached_requirements = _get_cached_requirements(requirements,
+                                                           __env__)
             if not cached_requirements:
                 return {
                     'result': False,