On Mon, 28 Jan 2019 at 09:04, Paul Moore email@example.com wrote:
On Sun, 27 Jan 2019 at 21:02, Thomas Kluyver firstname.lastname@example.org wrote:
On Sun, Jan 27, 2019, at 7:47 PM, Paul Moore wrote:
What is more difficult is the question of whether the PEP should change. As Chris pointed out, the previous discussion ended up saying that the build directory should not be on sys.path, but acknowledged that mandating that might cause issues. So the question now is, are the issues we've seen big enough that we want to change PEP 517 to say that the build directory *should* be on sys.path?
I don't see that this issue is an argument for changing the PEP. It seems like a problem with the backend that should be supporting legacy use cases. The rule about the frontend not using the CWD to load the backend doesn't constrain what the backend does once loaded.
From my perspective, the original arguments about the CWD still stand, but in addition PEP 517 is out now and there are tools implementing it, so it would be more disruptive to make changes. So at least for now, I'm -1 on changing the rule about the CWD.
Yes, that's my view too. I'm happy that we revisit the question, but personally, I remain in favour of the PEP as it stands.
Yep, I think letting the backend decide whether or not it wants to include the build directory on sys.path remains the right way to go.
Thomas's https://github.com/takluyver/intreehooks then addresses opting in to that in the general case, while Paul Ganssle's proposed build_meta_legacy backend in https://github.com/pypa/setuptools/pull/1652 addresses it for the specific case of setup.py execution.