[p_l]

That's honestly not the worst thing involved.

Another is that Nix as language is yet another of those "functional programming sounds fun, let's do bare minimal pure language and forget about all the niceties that proper ones figured out".

[mikepurvis]

I think my argument is that most of those issues are relatively shallow— they're problems that could be addressed with tweaks to the syntax or additions to the standard library.

The IFD issue is fundamental. It's why poetry2nix has to be implemented entirely in Nix code in order to run at evaluation time without blocking, whereas in a world where eval and build could properly interleave, this would never be done— the core logic of poetry2nix would be implemented in something sane.