We plan to merge DM-8467 to master on Monday morning (after the latest weekly, w_2017_10, has been tagged). This is a comprehensive change affecting almost all packages in lsst_distrib.
From that point on, all C++ to Python wrappers will be generated with Pybind11 Instead of Swig.
At the same time a new DM Pybind11 Style Guide (DM-8577) and a new step-by-step Pybind11 wrapping tutorial (DM-9089) will be merged. Please see these ticket branches for documentation.
How does this affect me?
- If you are using, or developing against, a stable release you won’t be affected at all. The latest,
13.0, release is still based on Swig. - If you are developing against the latest weekly, consider sticking to
w_2017_10for a while. Alternatively you can use the13.0release instead. - If you are developing in Python against master you might see small API changes (that will be documented in the release notes on Monday), but in general should not notice a major difference. The current Pybind11 switch attempts to minimize API changes from Swig. But Pybind11 enables more Pythonic API’s for wrapped C++ classes, so you may get nicer interfaces over time.
- If you are developing in C++ and your code needs to be called from Python, you will have to add Pybind11 wrappers. See the aforementioned documentation.
I’m about to merge some code, what should I do?
Even if it is a pure Python package (which will probably just work). If it is part of lsst_distrib, please let us know before merging. You can reach us on Slack at #dm-pybind11-porting, or reply to this post. We are also happy to assist you at the JTM hack session to help you add Pybind11 wrappers.
Can I try it already?
Yes. Using lsstsw you can issue:
rebuild -r tickets/DM-8467 lsst_distrib
to build a Pybind11 stack. Note that there will be quite some churn the coming days due to cleanup, commit squashing, etc. But please feel free to try it out!