@pyimport numpy throwing an error when precompiling a module

General Usage
1

Hi everyone !

I am running on a Mac (with M1 chip) and I am quite new to Julia. I am currently modifying an existing Julia package. I want to call/write some python code requiring importing numpy. However when precompiling (or executing a script involving that package I modified), the following line

@pyimport numpy as np

throw me the error

ERROR: LoadError: PyError (PyImport_ImportModule) <class 'RuntimeError'>
RuntimeError("Polyfit sanity test emitted a warning, most likely due to using a buggy Accelerate backend.\nIf you compiled yourself, more information is available at:\nhttps://numpy.org/doc/stable/user/building.html#accelerated-blas-lapack-libraries\nOtherwise report this to the vendor that provided NumPy.\nUserWarning: The value of the smallest subnormal for <class 'numpy.float64'> type is zero.\n")
  File "/Users/jcrismer/.julia/conda/3/lib/python3.9/site-packages/numpy/__init__.py", line 376, in <module>
    raise RuntimeError(msg)

On the other hand, when I just write a script (outside of that package I am editing) I can import numpy without any issues. I am thus a bit confused about that.

I understand that I should find a way to tell Julia not to use Accelerate to precompile but I do not know how to do it. I am also surprised to be able to import numpy in a simple script (outside of that package).

I already browsed the internet a lot to find a solution but it was not successful until now. Some help would thus be really appreciated.

2

no, Julia doesn’t care at all, what you need to do is tell PyCall.jl which Python you want to use

3

this is vastly outdated syntax

4

From the PyCall documentation, it looks like you need to do the actual python imports inside your module’s __init__ method (which is called when the module is loaded rather than when it’s precompiled). Check out the example at the end of this section: GitHub - JuliaPy/PyCall.jl: Package to call Python functions from the Julia language

5

Indeed you are right! The way to call python packages is different for a simple script or for a module, which I did not suspect.

Thanks a lot!

6

Yeah, this is a common pitfall with modules (which are always precompiled by default). The rule of thumb I use is that it’s generally fine to do anything purely in Julia at the top level of a module, but as soon as you start interacting with another language or system (like creating C function pointers or python wrappers), you need to do your work in __init__. For more detailed information, see: Modules · The Julia Language

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