Header path handling on Windows

[michaelsbradleyjr]

This issue is possibly related to #284, but it seemed to me like a distinct issue and I was still poking at the problem, so I waited to raise it.

To be more precise, I ran into this problem after I put a workaround in place for #284.

I'm using nimterop to work with a library that provides alternative header files, the choice of one or another header depending on which lib features you plan to use.

So I have this kind of thing in my wrapper:

const thelibHeaderRelPath {.strdefine.} =
  "include" / "thelib" / "some.h"

And I pass thelibHeaderRelPath as the first argument to nimterop's getHeader, along with other appropriate arguments.

On Linux and macOS, this approach works as I expected. But it does not work on Windows, where my build environment is an MSYS2 Bash shell in MSYS2's UCRT64 environment.

After poking around in nimterop, I hit on a solution that involves a change in my code instead of nimterop's:

const thelibHeaderRelPath {.strdefine.} =
  when defined(windows):
    "include\\\\thelib\\\\some.h"
  else:
    "include" / "thelib" / "some.h"

Given that it works, it's suggestive that somewhere in nimterop's getHeader macro, and/or a helper function, path handling is having an issue with the \ path separator on Windows (or maybe just Windows when the Nim compiler is invoked from MSYS2 Bash, I'm not sure).

I've tried to figure out a change/fix to the nimterop code, but have so far been unsuccessful.

[genotrance]

Some log output might help to figure out where this is happening. There might be a missing quoteShelll in some shell call.

[michaelsbradleyjr]

I stuck echos all over the place, turned up verbosity, etc. I couldn't figure out where exactly it's happening. But I'm pretty confident it's happening in proc findFiles because in the case I described on Windows+MSYS2, when the relative path is "include" / "thelib" / "some.h", that proc returns an empty seq, but finds the file when the relative path is "include\\\\thelib\\\\some.h".

[genotrance]

Maybe print out the loaf cmd and the actual output? Might give some ideas what's being passed in for the passing and failing cases.