Merge pull request #978 from atugushev/compat-pip-19.4-pr-7290

Fix compatibility with pip master (pip>=19.4)

piptools/repositories/pypi.py

@@ -202,6 +202,10 @@ def resolve_reqs(self, download_dir, ireq, wheel_cache):
  )
  resolver_kwargs["make_install_req"] = make_install_req
 
+ if PIP_VERSION >= (19, 4):
+ preparer_kwargs["session"] = self.session
+ del resolver_kwargs["session"]
+
  resolver = None
  preparer = None
  with RequirementTracker() as req_tracker:
@@ -219,8 +223,7 @@ def resolve_reqs(self, download_dir, ireq, wheel_cache):
  if PIP_VERSION < (19, 4):
  resolver.require_hashes = require_hashes
  results = resolver._resolve_one(reqset, ireq)
- else: # pragma: no cover
- # TODO remove pragma after pip==19.4 being released
+ else:
  results = resolver._resolve_one(reqset, ireq, require_hashes)
 
  reqset.cleanup_files()