Error in iisignature.prepare(3, 3) function with small dimensions

[Pzlipzli]

iisignature == 0.24
Python == 3.9
macOS

1. Run the following code:
   prep = iisignature.prepare(3, 3)
2. See this message: problem freeing buf
3. And see this error:
   Traceback (most recent call last):
   RuntimeError: overflowed buffer in push()
4. If I run prep = iisignature.prepare(10, 3), it works well.

In fact, if I change the first number to any number smaller than 10, the same error occurs.
I wonder if it is a bug. Looking forward to your reply. Thanks.

[bottler]

Let me guess that you are using a Mac with an arm-based processor like M1 M2 or M3. You are suffering from the problem described in #18 . Basically, the compiled code does not work on your processor, and iisignature is failing to notice this.

For a quick workaround, I can suggest the same thing as I did on that issue, namely use iisignature.prepare(3, 3, "O") etc.

In terms of solving the problem, I see two possibilities:

• Are you not using the latest version of the code from the master branch? If you are using an old version, then you won't have the fix in 2647308 in which case this problem will be expected. For these purposes, the latest version 0.24 counts as an old version, I am afraid. Because this library changes so rarely, we have not bothered to make new versions.

• (the scary possibility) perhaps the fix does not work, because the build system does not define __arm__. I if you think this might be the case, are you in a position to help investigate this? Which compiler and OS and processor might you be running?

[Pzlipzli]

Thank you so much for your explanation. iisignature.prepare(3, 3, "O") works.
And thank you for this project. It is very useful.

[bottler]

But can you confirm which version you have / how you did the installation? It may be there's still something to fix here.

[Pzlipzli]

It is 0.24 and I installed it by pip install iisignature because ChatGPT suggested me doing this.

[bottler]

I did just push a fix to this: a recent mac M3 wasn't defining __arm__ so I check __ARM_ARCH. 5e53d87