[pypy-issue] Issue #2978: Avoid timeouts - extra dot in graphlib (pypy/pypy)

[Stefano Rivera]

New issue 2978: Avoid timeouts - extra dot in graphlib
https://bitbucket.org/pypy/pypy/issues/2978/avoid-timeouts-extra-dot-in-graphlib

Stefano Rivera:

Debian has had some issues with pypy builds timing out on some of our slower architectures. [Logs](https://buildd.debian.org/status/logs.php?pkg=pypy).
I brought this up on IRC a while ago (probably at least a year), and planned to go digging for some place to insert `log.dot()` calls. Armin was not very hopeful that I'd find useful places to do this, as we don't want to emit a dot unless the build is actually progressing, and not stuck in a loop.

Anyway, I found 1 place that made a big difference for us. So, I thought I'd share the patch.
 
I'm happy to test variants of this on MIPS64, which was timing out most "reliably".

I'd say the next most frequent cause of timeouts is in the test harness for cpyext., e.g. [log](https://buildd.debian.org/status/fetch.php?pkg=pypy&arch=kfreebsd-i386&ver=7.0.0%2Bdfsg-3&stamp=1553476497&raw=0)