As you can see, pip thinks the last 6 URLs have the "wrong project name" because the url uses PyQt-mac-gpl-4.11.3.tar.gz instead of explicitly saying "PyQt4". Is there anyway to account for this case?

i resolved the issue by removing my (global) installation of python3-pyqt4. since the global python3 packages are available to a local python3.7 environment, pyqtgraph was finding PyQt4, importing it, ...