Minor comment typo.
@@ -74,7 +74,7 @@ class RequirementPreparer(object):
self.build_dir = build_dir
self.req_tracker = req_tracker
- # Where still packed archives should be written to. If None, they are
+ # Where still-packed archives should be written to. If None, they are
# not saved, and are deleted immediately after unpacking.
if download_dir:
download_dir = expanduser(download_dir)
