Reducing "You found a bug" reports

[Ian Eure <ian@retrospec.tv>]

There’s a steady number of bug reports generated by the "You found 
a bug" message which happens during `guix pull's.  The 
overwhelming majority of these reports are caused by networking 
problems or the Guix infrastructure being unreliable or 
overloaded.  Many of these were submitted during the recent 
guix.gnu.org downtime.

Some of these that I see:

55066
62023
62830
61520
58309

...I’m sure there are many more.

Is there some way for this code to be smarter about when it prints 
the "report a bug" message, so it doesn’t tell users to report 
bugs when none exist?  Is there a way for it to notice that the 
problem is related to networking, and tell the users to try again 
in a little while?  Is it worth removing the "report a bug" 
message entirely?

It doesn’t feel great to tell users to report a bug for things 
that aren’t bugs.  They’re either closed, or never followed up on; 
it’s a poor experience on both ends.

Thanks,

  — Ian