[pypy-issue] Issue #2103: PyPy fails to run with JIT and PAX enabled, doesn't produce a relevant error (pypy/pypy)

[Bartosz Wróblewski]

New issue 2103: PyPy fails to run with JIT and PAX enabled, doesn't produce a relevant error
https://bitbucket.org/pypy/pypy/issues/2103/pypy-fails-to-run-with-jit-and-pax-enabled

Bartosz Wróblewski:

Tagging issue #2086 as well, since this happens on Alpine in particular.

After compiling PyPy with JIT enabled, on a system with PAX, running the interpreter will fail and return a `MemoryError` to the user, with no further comments.

Running with `--jit off` does resolve the issue, at the obvious expense of disabling JIT.

It is possible to run `paxctl -cm pypy-c` to opt-out of the PAX subsystem, as well.


Building through the Makefile will not trigger the problem immediately, but a build through `pypy rpython/bin/rpython --opt=jit pypy/goal/targetpypystandalone.py` will fail just after the compilation phase, again, producing no useful error.

A brief note outlining the issue should be added to the wiki build instructions.

Ideally, the build system should detect PAX on linux hosts, and alert the user.

Within PyPy itself, perhaps a better message could be returned if the failing mmap sets the error code to EPERM?