Yes, the pyparsing API seems to have stabilized since that message was written, and we currently ship "vanilla" pyparsing 1.5.5. However:

1. This PR is far from complete -- matplotlib itself needs to be updated to depend on and use a globally installed pyparsing. Are you sure you have tested matplotlib with pyparsing 1.5.6 and all unit tests pass?

2. In the Windows and OS-X binaries, we ship third-party libraries to make installation easier. See how we handle dateutil and pytz. The same needs to be done here.

3. Ultimately, this should be done in the larger context of Use automatic dependency installation #1157. We don't have a good solution to that yet, but whatever it is needs to have no impact on those using the Windows and OS-X binaries.

Fair enough, I'll work on less intrusive solution. Perhaps, checking for system pyparsing and fallback to bundled one if former is not found?

Yes -- that's what we do with dateutil and pytz at the moment.

Oh geez, I've made a mess... I wasn't aware that all my random commits will be subject to validation via Travis. Sorry for wasting your cycles.

Don't worry about wasting our cycles -- you're saving a lot of our human cycles by working on this!

You may also be interested in MEP11 -- which began in part as a result of this PR -- and the associated discussion on the mailing list.

@mdboom & @Xarthisius - where does this sit with the new setup machinery? Is this now obsolete?

@pelson: Thanks for pointing this out again. Yes, as of 1.3.0, pyparsing is unbundled and will be installed by pip if the user installs that way.