Package download fails for duplicate tarballs

[vbraun]

There is a general issue with tarballs being shared between packages: the mirror url cannot be uniquely determined. E.g. now the gap tarball might be at

• ​http://files.sagemath.org/spkg/upstream/gap/gap-4.10.0.tar.gz
• ​http://files.sagemath.org/spkg/upstream/gap_packages/gap-4.10.0.tar.gz

This leads to the build failure

Traceback (most recent call last):
  File "/var/lib/buildbot/slave/sage_git/build/build/bin/../sage_bootstrap/download/cmdline.py", line 118, in run_safe
    run()
  File "/var/lib/buildbot/slave/sage_git/build/build/bin/../sage_bootstrap/download/cmdline.py", line 100, in run
    app.download_tarball(args.url_or_tarball, args.destination)
  File "/var/lib/buildbot/slave/sage_git/build/build/bin/../sage_bootstrap/download/app.py", line 43, in download_tarball
    tarball.download()
  File "/var/lib/buildbot/slave/sage_git/build/build/bin/../sage_bootstrap/tarball.py", line 162, in download
    raise FileNotMirroredError('tarball does not exist on mirror network')
sage_bootstrap.tarball.FileNotMirroredError: tarball does not exist on mirror network

For now I'll just download the tarball to both upstream locations but thats a stupid workaround

[embray]

Retarging tickets optimistically to the next milestone. If you are responsible for this ticket (either its reporter or owner) and don't believe you are likely to complete this ticket before the next release (8.7) please retarget this ticket's milestone to sage-pending or sage-wishlist.

[embray]

Ticket retargeted after milestone closed (if you don't believe this ticket is appropriate for the Sage 8.8 release please retarget manually)

[embray]

As the Sage-8.8 release milestone is pending, we should delete the sage-8.8 milestone for tickets that are not actively being worked on or that still require significant work to move forward. If you feel that this ticket should be included in the next Sage release at the soonest please set its milestone to the next release milestone (sage-8.9).