bug#32895: file progress reporter crashes on small files

[Ricardo Wurmus]

Ludovic Courtès <address@hidden> writes:

> Hello,
>
> Ricardo Wurmus <address@hidden> skribis:
>
>> guix/progress.scm:214:25: In procedure display-download-progress:
>> In procedure /: Wrong type argument in position 1: #f
>>
>> This happens because “transferred” in the “else” branch of (@ (guix
>> progress) display-download-progress) is #f instead of a number.  This
>> could be the result of running string->number on an invalid string in
>> “print-build-event”.
>
> Indeed, that seems to be the case.  This would mean we’re emitting an
> incorrect build trace.
>
> Do you have the exact command to reproduce it?

Unfortunately, I don’t.  It’s hard to reproduce this when all these
cabal revisions have already been downloaded.  This also depends a lot
on the actual download speed.

I only got this for cabal revisions, so locally building any of the
ghc-* packages with #:cabal-revision arguments might be sufficient to
trigger the bug.

--
Ricardo