[Speed] speed.python.org: recent issues to run benchmarks

[Victor Stinner]

Hi,

tl;dr I'm trying to run benchmarks with PGO, but I get new errors, so
speed.python.org is currently broken.

Last december, I upgraded the speed-python server (server used to run
benchmarks for CPython) from Ubuntu 14.04 (LTS) to 16.04 (LTS) to be
able to compile Python using PGO compilation. On Ubuntu 14.04, GCC
failed with an internal error. Sadly, I lost my sudo permission during
the upgrade: it took almost one month to retrieve the permission.

I removed all results from speed.python.org to start to publish new
benchmark results of LTO+PGO compilation. Sadly, I got new not funny
errors.

The first benchmark on the 2.7 branch failed because of a recent
regression specific to the 2.7 branch (now fixed):
http://bugs.python.org/issue28871#msg284145

I fixed my configuration file to only test a list of revisions instead
of starting by testing all branches. One more time, benchmarks failed:
this time, the "python3 -m performance venv recreate" failed on the
creation of the virtual environment:

* It seems like "python -m ensurepip --verbose" failed, whereas it
works well usually. I didn't understand how/why the command failed.
* Running get-pip.py (https://bootstrap.pypa.io/get-pip.py) also
failed for an unknown reason
* virtualenv also failed, probably because the system virtualenv
command was outdated (virtualenv didn't copy _collections_abc in the
venv which is required in Python 3.6)

performance has multiple functions to create the venv, but all failed.
I'm really unlucky.

I modified my scripts to run benchmarks (scripts/ directory of the
performance project) to handle errors more nicely. For example, don't
fail immediately, but log errors.

I also modified performance to flush stdout+stderr before running
subprocess to not mess logs (when stdout and/or stderr are
redirected).

I'm now trying to run benchmarks one more time... ;-)

Victor