Alignment issue using EigenPy for custom type

[ofloveandhate]

Hi! I use EigenPy to expose Eigen with my custom numeric type (Boost::Multiprecision complexes, which i'll call mpc) with dynamically sized matrices into Python.

I'm encountering an issue in Python where I have a numpy array of mpc, as output from one function call, and I'm feeding it into another function expecting an Eigen matrix of mpc. But I'm getting

Assertion failed: (is_aligned(raw_ptr, EIGENPY_DEFAULT_ALIGN_BYTES) && "The pointer is not aligned."), function allocate, file eigen-allocator.hpp, line 229.
Abort trap: 6

I'm looking for advice on how to go about debugging this. I can produce backtraces, etc, but I figured I'd start by asking for advice since I suspect you've encountered this before -- I bet you have the assert there to help find this issue, and maybe there's a simple "thing I should be doing".

I'd appreciate any help you can give me. Thanks a billion!

[ofloveandhate]

Is this related to Issue #330 ?

[ofloveandhate]

Well, I was able to work with the debugger, and indeed the pointer is not 16-aligned. So now I need to go back in my code and find out where that container was made, and make sure it's 16-alignining at that location.

I'm so confused, though, because the Eigen documentation suggests repeatedly that fixed-size containers exhibit alignment issues. But my code only works with dynamically sized containers, and indeed this problem I'm encountering is with dynamic-length vectors, not fixed-size. Soooo... I move forward trying to chase down the source of this vector and make sure its creator knows to 16-align them.

[jcarpent]

Could you provide a reproducible example?

[ofloveandhate]

Thanks for your reply. I will increase the priority of this in my list of todo's. A MWE would indeed be great.

As I work toward one, have you experienced alignment issues ever between arrays made with numpy and functions in EigenPy / Pinnochio / etc?

[ofloveandhate]

I'm trying to write a reproducible example, but I'm struggling to get eigenpy / my previous example to compile on my machine, due to an issue with finding Python. argh.

[ofloveandhate]

I finally was able to get my example "library" compiling and importing correctly using conda, so now I can make progress on my MWE for my alignment issue.