I've been able to use spaces and other meaningful punctuation in my paths for decades now
Well ... spaces don't work for me ... and although I don't need it to work for me, I'd be most interested to learn how you've achieved it.
First up, I put a build of ActivePerl 5.8.8 (build 822) in:
C:\_32\with spaces\perl
and I placed a copy of the MathFFT1.28 source in
C:\_32\with spaces\MathFFT1.28
and I tried to build MathFFT1.28 (using the above mentioned build of perl). If I use dmake, 'perl Makefile.PL' runs ok, but 'dmake' fails immediately with:
dmake: Error:  `C:\_32\with' not found, and can't be made
So I ran 'dmake realclean' and then set things up to use 'nmake' instead of 'dmake'. Again, 'perl Makefile.PL' runs fine, but 'nmake' croaks immediately with:
NMAKE : fatal error U1073: don't know how to make 'C:\_32\with'
Stop.
Below my sig is a copy'n'paste of what I did. How have you got around these problems ? (An answer to that could put us well on the way to coming up with a patch for Inline.)
Cheers, Rob
C:\_32\with spaces\MathFFT1.28>perl V:make
make='dmake';
C:\_32\with spaces\MathFFT1.28>perl makefile.PL
Set up gcc environment  3.4.5 (mingw32 special)
Checking if your kit is complete...
Looks good
Writing Makefile for Math::FFT
C:\_32\with spaces\MathFFT1.28>dmake
dmake: Error:  `C:\_32\with' not found, and can't be made
C:\_32\with spaces\MathFFT1.28>dmake realclean
.
[snipped  nothing of interest here]
.
C:\_32\with spaces\MathFFT1.28>set PATH=C:\_32\nmake;%path%
C:\_32\with spaces\MathFFT1.28>perl V:make
make='nmake';
C:\_32\with spaces\MathFFT1.28>perl Makefile.PL
Set up gcc environment  3.4.5 (mingw32 special)
Checking if your kit is complete...
Looks good
Writing Makefile for Math::FFT
C:\_32\with spaces\MathFFT1.28>nmake
Microsoft (R) Program Maintenance Utility Version 7.00.9466
Copyright (C) Microsoft Corporation. All rights reserved.
NMAKE : fatal error U1073: don't know how to make 'C:\_32\with'
Stop.
C:\_32\with spaces\MathFFT1.28>
