Bug 1252343

When trying to build from an SRPM hosted on dropbox copr builds fail with a weird error message:
[2015-08-07 13:19:21,547][ ERROR][PID:12267] builder.build error building pkg `https://dl.dropboxusercontent.com/s/6ib68tn3uoqf4f6/thermostat-1.99.5-4.fedora.src.rpm`: BuildError: rc 2 not in success_codes; return code: 2; stdout: starting logfile: None

An example build URL is here:
https://copr.fedoraproject.org/coprs/jerboaa/thermostat-latest/build/107400/

I've been told that this is due to an unknown problem in mockchain. Perhaps this is worth fixing? FWIW, I can download the SRPM via wget or curl just fine:

$ wget https://dl.dropboxusercontent.com/s/6ib68tn3uoqf4f6/thermostat-1.99.5-4.fedora.src.rpm

Note that in theory copr should be able to build from any publicly accessible URL. Doesn't seem like it in practice. It's also worth pointing out that we push those builds via a CI RPM builder which is automated and I rather use a shared dropbox account than copying a private SSH key to the builder in order to be able to use fedorapeople.org or some such for uploading the SRPM.

Bug 1045744 will somewhat help. However, it seems it's not yet fixed. Nevertheless, I think this should get investigated at least as to why it's failing to download from a shared dropbox URL.