Debian u1 patches

[infinity0]

This ticket lists some Debian patches that we're applying to Sage. They should be fairly non-controversial.

• #22437
• #22438
• #22439
• #22440
• #22441
• #22442
• #22443
• #22444
• #22445

(We have other patches which need some more work and discussion; I'll be submitting those later as well.)

These were taken from our 7.5.1 branch, which is a WIP. They applied cleanly to 7.6, apart from a trivial merge conflict fix in the case of "Don't fail plot.py". However I haven't tested it on a non-Debian install yet (I don't have the build resources for that right this minute).

[infinity0]

New commits:

​084b452	Use system paths for libGAP
​d1ce385	Use lexists instead of exists
​317aef6	Fix Sage's use of scipy rtol parameter
​b50511f	Work around python bug #1652
​29962ec	Don't fail plot.py doctest if DISPLAY is unset
​9dd9258	Compile pynac interface with SINGULAR_CFLAGS to find its headers
​e9baf21	Do not test the version of glpk

[git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

​bd439fb	Use system paths for libGAP
​b91b5a7	Use lexists instead of exists
​49b5625	Fix Sage's use of scipy rtol parameter
​9bbceda	Work around python bug #1652
​6ac7288	Don't fail plot.py doctest if DISPLAY is unset
​68152df	Compile pynac interface with SINGULAR_CFLAGS to find its headers
​27d41fa	Do not test the version of glpk

[infinity0]

Re-did the commits because the older ones leaked my local host name. Whoops...

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​316c6c3	Fix atrocious logic in symlink()
​399f911	Make sage.doctest.sources.get_basename work in more situations

[jdemeyer]

I would much prefer to have one ticket for each issue that you are fixing instead of grouping together a bunch of unrelated patches.

[infinity0]

Some of these commits are very small and opening a new ticket just for a single-line commit seems like unnecessary overhead. The libgap and scipy ones are a bit larger. Shall I still split everything or would you be happy with me splitting out only these two?

[jdemeyer]

One ticket per issue. If that means 10 tickets, then so be it.

[infinity0]

Reopened as #22437, #22438, #22439, #22440, #22441, #22442, #22443, #22444, #22445.

You can close this ticket. I tried but it doesn't look like I have the permissions.

[vdelecroix]

Better to keep this ticket as a task ticket... changed accordingly

[vdelecroix]

(and thanks for the effort of proposing the patches to Sage!)

[infinity0]

welcome! I've fixed the missing branches, I think it is something to do with the fact that trac logs me out every 10 minutes or so (because I connect through Tor).. will keep an eye out on that in the future