setup_venv: Fix handling of Git requirements.

get_package_names did not correctly strip the GitHub URLs from package
names, resulting in the "package names" for our dependencies installed
from Git being tracked with the complete sha1sum included in the name.
This meant that upgrading our virtualenvs incorrectly ended up
resorting to creating an entirely new virtualenv whenever we changed a
dependency that had previously been installed from GitHub URLs.

scripts/lib/setup_venv.py

@@ -45,6 +45,13 @@ def get_package_names(requirements_file):
     cleaned = []
     operators = ['~=', '==', '!=', '<', '>']
     for package in packages:
+        if package.startswith("git+https://") and '#egg=' in package:
+            split_package = package.split("#egg=")
+            if len(split_package) != 2:
+                raise Exception("Unexpected duplicate #egg in package %s" % (package,))
+            # Extract the package name from Git requirements entries
+            package = split_package[1]
+
         for operator in operators:
             if operator in package:
                 package = package.split(operator)[0]