A common problem is building a command line with paths created with such a Windows-aware joinPath function and then executing that command line.

If that execution is handled by a shell instead of going directly through an operating system's CreateProcess() function, then the command line string may be mangled either by the shell, or some other "helpful" code sitting inbetween which tries to resolve backslash-escapes (which are usually needed in front of quotation marks).

It a very typical problem in cross-platform Python code, and I think I also stumbled over it in Node.js.