See https://github.com/JuliaLang/julia/pull/13542 … like in Python (PEP 235), we decided to make module loading (using Foo) case-sensitive on case-insensitive case-preserving filesystems.
Is this requirement documented anywhere?
This is documented in the manual under https://docs.julialang.org/en/latest/base/base/#Base.require
How does this work if I say, clone someone’s repo who’s been on a case-insensitive filesystem?
Virtually all modern filesystems are either case-sensitive or case-insensitive but case-preserving. On the latter (Mac and Windows) systems, the case information is not lost, so you are fine.
Do you have a real need to support source code on case-insensitive case-destroying filesystems?