mpy-cross: Assertion failed when compiling tests/basics/exception_chain.py.
Port, board and/or hardware
Unix on Linux/amd64
MicroPython version
MicroPython v1.26.0-preview.261.gbcc8d4ee1.dirty on 2025-06-22; linux [GCC 15.1.1] version
Reproduction
- Build mpy-cross with no special flags (
make -C mpy-cross clean && make -C mpy-cross) - Compile
tests/basics/exception_chain.pyinto native code (arch does not matter) withmpy-cross -X emit=native -march=debug tests/basics/exception_chain.py mpy-crosswill crash.
Expected behaviour
Compiling tests/basics/exception_chain.py should not crash mpy-cross.
Observed behaviour
mpy-cross crashes with:
mpy-cross: ../py/emitnative.c:2947: emit_native_raise_varargs: Assertion `n_args == 1' failed.`
Additional Information
If having a multi-arg exception is not supported for native code compilation, then an error message should be printed rather than crashing the compiler.
Code of Conduct
Yes, I agree
Native & viper failures with setjmp exception handling
Port, board and/or hardware
unix
MicroPython version
MicroPython v1.26.0-preview.169.g429478dcfc.dirty on 2025-06-02; linux [GCC 12.2.0] version
(modified from v1.26.0-preview-166-gc0111e63b3)
Reproduction
- grab my branch at https://github.com/jepler/circuitpython/tree/coverage-setjmp
- in ports/unix
make VARIANT=coverage_setjmp test
Expected behaviour
Expected all tests to pass
Observed behaviour
The native_gen.py test fails with a segfault. This is the minimized version of the crashing code:
# catching an exception from .throw()
@micropython.native
def gen3():
try:
yield 1
except Exception as er:
print("caught", repr(er))
g = gen3()
print(g.throw(ValueError(42)))
Additional Information
The branch above has 3 changes:
- introduce a unix variant that uses setjmp for exception handling
- fix a build error in
mp_native_yield_from - turns on N_NLR_SETJMP in emitnative whenever MICROPY_NLR_SETJMP is enabled and N_NLR_SETJMP is not otherwise used (note: this fixes other errors in
make testthat occur with MICROPY_NLR_SETJMP enabled)
It is vaguely possible that my change in mp_native_yield_from is wrong and I considered whether it might contribute to the crash, but in my reduced testcase a gdb breakpoint on that function isn't hit so I don't think that's it.
Code of Conduct
Yes, I agree