gnumake 3.78.1 vs. 3.79.1: Directory as File Error?

[Randy Yates]

I'm running 3.78.1 on a Solaris machine and 3.79.1 on the
PC under XP. My build runs fine on Solaris, but under XP
I get the following error (the relevent excerpt from 
make -d):

*******************************************************************
  Considering target file `s:/commondsp_sw/lib/wavefile.a'.
    Considering target file `s:/commondsp_sw/src/wavefile/nativepc/wavefile.o'.
     File `s:/commondsp_sw/src/wavefile/nativepc/wavefile.o' does not exist.
      Pruning file `s:/commondsp_sw/src/wavefile/wavefile.c'.
      Considering target file `s:/commondsp_sw/src/wavefile/nativepc/'.
       File `s:/commondsp_sw/src/wavefile/nativepc/' does not exist.
       Finished prerequisites of target file 
`s:/commondsp_sw/src/wavefile/nativepc/'.
      Must remake target `s:/commondsp_sw/src/wavefile/nativepc/'.
mkdir s:/commondsp_sw/src/wavefile/nativepc/
CreateProcess(c:\cygwin\bin\mkdir.exe,mkdir 
s:/commondsp_sw/src/wavefile/nativepc/,...)
Putting child 0x009cf4d0 (s:/commondsp_sw/src/wavefile/nativepc/) PID 10293864 
on the chain.
Live child 0x009cf4d0 (s:/commondsp_sw/src/wavefile/nativepc/) PID 10293864 
mkdir: cannot create directory `s:/commondsp_sw/src/wavefile/nativepc/': File 
exists
*******************************************************************

I have a build rule for the directory
s:/commondsp_sw/src/wavefile/nativepc/ (just mkdir it), which you see
being executed above. The question is, why didn't make 3.79.1 see that
the directory already existed. It seems like make is distinguishing
between a file and a directory in version 3.79.1, but not in
3.78.1. Is this true?

The entire -d output is attached below.
-- 
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
randy.yates@sonyericsson.com, 919-472-1124

makeerror.txt
Description: Text document