fix(up): solution serialization sometime failed in the presence of non-symbolic parameters

[arbimo]

fix #140

[arbimo]

@nicola-gigante It seems that the CI now fails with the same error you encountered recently. Any hint on how to fix this?

My suspicion is that a new deployment to PIP was not backward compatible, and breaks the default installation (as UP does not impose strict version numbers on its dependencies).

[nicola-gigante]

Hi @arbimo, the fix was to remove numpy 2.0 and install any version of the 1.x line, because the incompatibility is between some package and numpy 2.x. In my project I just added numpy<2 in requirements.txt, I'm not sure what to do here precisely.

[arbimo]

Yep, requesting numpy < 2 on top of the UP requirements worked. Thanks for the tip, these two hours of yours were not completely wasted ;)

I have opened a PR on unified-planning to add this workaround upstream as well: aiplan4eu/unified-planning#617

The fix should be available in the development build now.

[nicola-gigante]

I'm glad it was time well spent 🤣 thanks!