Hello world Segmentation fault

[HugoGranstrom]

I tried running the hello world example:

import nimpy/py_lib
pyInitLibPath("/home/hugo/miniconda3/lib/libpython3.9.so.1.0")

import nimpy

proc greet(name: string): string {.exportpy.} =
  return "Hello, " & name & "!"

I compiled it like this: nim c --app:lib --out:mymodule.so --threads:on mymodule.nim

And the Python code:

import mymodule
print(mymodule.greet("Hugo"))

But I'm getting this error when running the python file:

Traceback (most recent call last)
/home/hugo/.nimble/pkgs/nimpy-0.2.0/nimpy.nim(674) greetPy_wrapper
SIGSEGV: Illegal storage access. (Attempt to read from nil?)
Segmentation fault (core dumped)

It somehow seems to be the string (seq also fails, so feels like something with the GC) that's causing this, because if I change the function to this version with an int instead, it works:

proc greet(name: int): string {.exportpy.} =
  return "Hello, " & $name & "!"

I have tried compiling with arc as well, but the same error. Any idea why this is happening?

Versions

• PopOS (Ubuntu 22.04)
• Nim Compiler Version 1.6.6 [Linux: amd64]
• Anaconda Python 3.9.12

[yglukhov]

Please make absolutely sure you're using latest nimpy (delete and reinstall). Otherwise I cannot reproduce this.

[HugoGranstrom]

It seems like it was the pyInitLibPath("/home/hugo/miniconda3/lib/libpython3.9.so.1.0") that was the trouble. I fixed the thing that required me to have it, and now it works :) So it was just some local problems I guess.