nonsensical TypeError from "-X jit -m compile --static"

[belm0]

good (no options):

$ docker run -v $PWD:/vol -it --rm ghcr.io/facebookincubator/cinder-runtime:cinder-3.8 vol/cinder_typed_prim_bug.py
done 0.57

bad (-X jit -m compile --static):

$ docker run -v $PWD:/vol -it --rm ghcr.io/facebookincubator/cinder-runtime:cinder-3.8 -X jit -m compiler --static vol/cinder_typed_prim_bug.py
Traceback (most recent call last):
  File "/cinder/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/cinder/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/cinder/lib/python3.8/compiler/__main__.py", line 122, in <module>
    exec(codeobj, d, d)
  File "vol/cinder_typed_prim_bug.py", line 15, in __main__
    main()
  File "vol/cinder_typed_prim_bug.py", line 10, in main
    c += foo(.4, .97)
TypeError: unsupported operand type(s) for +=: 'float' and 'function'

The compiler is acting as if the written code were c += foo rather than c += foo(.4, .97).

The problem goes away by removing -X jit, --static, or use of the double primitives.

cinder_typed_prim_bug.py

from __static__ import double

def foo(a: double, b: double) -> double:
    return b - a

def main():
    c = 0.
    c += foo(.4, .97)
    print('done', c)

if __name__ == '__main__':
    main()

seen in cinder-3.8.6c2de94

[belm0]

Here is a fix to main() to make it work (adding primitive type on var c):

def main():
    c: double = 0.
    c += foo(.4, .97)
    print('done', box(c))

Even if that's required, the error output is wrong.

[belm0]

In a more complete program than this simple repro, I've seen it manifest more severely, namely a SIGSEGV. Fixing the primitive typing on c fixed that program as well. (I'm not sure how to have docker run show the trace, otherwise I'd share it.)

[carljm]

The explicit c: double should be required, we don't auto box or unbox within static code (only at function call boundaries between static and non-static code). But clearly there's a bug in the compiler on the way to delivering that error. Thanks for the report!