Crash on Apple M1 with Julia 1.8-rc1

[gnuille]

When initializing the juliacall module on a machine with an apple M1, it crashes:

% python -c "import juliacall"
fatal: error thrown and no exception handler available.
ErrorException("could not load symbol "jl_n_threads":
dlsym(RTLD_DEFAULT, jl_n_threads): symbol not found")
ijl_errorf at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
ijl_dlsym at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
ijl_load_and_lookup at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
nthreads at ./threadingconstructs.jl:23 [inlined]
__preinit_threads__ at ./task.jl:706
jfptr___preinit_threads___50438 at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
ijl_apply_generic at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
_finish_julia_init at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
julia_init at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
ijl_init at /Applications/Julia-1.8.app/Contents/Resources/julia/lib/julia/libjulia-internal.1.8.dylib (unknown line)
ffi_call_SYSV at /usr/lib/libffi.dylib (unknown line)

Using PDB I have been able to locate and isolate the issue although I don't understand why the crash is caused.

The line that crashes is:
https://github.com/cjdoris/PythonCall.jl/blob/73ae3059032c6951f9f0856494add524e798c05a/pysrc/juliacall/__init__.py#L124

A minimal example that reproduces the issue:

import ctypes
lib = ctypes.CDLL("/Applications/Julia-1.8.app/Contents/Resources/julia/lib/libjulia.1.8.dylib")
lib.jl_init__threading()

[giordano]

Duplicate of #175?

[gnuille]

Yes, sorry