This creates burden on maintainers to keep those urls up-to-date as version changes, so I created simple python script for printing out Source urls from spec files:
spec_obj = ts.parseSpec(sys.argv)
sources = spec_obj.sources
for url, num, flags in sources:
Chmod this +x, put into your PATH and enjoy by giving it path to spec file.
*Edit*: Probably much nicer way to do the same thing already present on your system (courtesy of Alexander Kurtakov):
I knew there was something like this, but forgot what it was. Oh well…2 minutes lost.