The following reply was made to PR toolchain/29032; it has been noted by GNATS.

From: Hiroyuki Bessho <bsh@grotto.jp>
To: gnats-bugs@NetBSD.org
Cc: 
Subject: Re: toolchain/29032
Date: Wed, 18 Apr 2007 08:01:33 +0900

 I could fix the problem and succeeded to build NetBSD/i386 on Cygwin
 with following patch.
 
 Index: tools/asn1_compile/Makefile
 ===================================================================
 RCS file: /u0/cvsupbase/cvsroot-netbsd/src/tools/asn1_compile/Makefile,v
 retrieving revision 1.4
 diff -u -r1.4 Makefile
 --- tools/asn1_compile/Makefile	8 Dec 2002 20:19:57 -0000	1.4
 +++ tools/asn1_compile/Makefile	17 Apr 2007 22:49:29 -0000
 @@ -3,4 +3,13 @@
  HOSTPROGNAME=	${_TOOL_PREFIX}asn1_compile
  HOST_SRCDIR=	lib/libasn1/asn1_compile
  
 +BUILD_OSTYPE!=  uname -s
 +.if ! empty(BUILD_OSTYPE:MCYGWIN*)
 +# Cygwin doesn't have arpa/nameser.h
 +_BINDDIR=${.CURDIR}/../../dist/bind
 +HOST_CPPFLAGS+=	-idirafter ${_BINDDIR}/lib/bind/include
 +HOST_CPPFLAGS+= -idirafter ${_BINDDIR}/lib/bind/port/cygwin/include
 +.endif
 +
  .include "${.CURDIR}/../Makefile.host"
 Index: tools/compile_et/Makefile
 ===================================================================
 RCS file: /u0/cvsupbase/cvsroot-netbsd/src/tools/compile_et/Makefile,v
 retrieving revision 1.5
 diff -u -r1.5 Makefile
 --- tools/compile_et/Makefile	16 Nov 2003 14:14:18 -0000	1.5
 +++ tools/compile_et/Makefile	17 Apr 2007 22:49:29 -0000
 @@ -19,6 +19,14 @@
  	${_MKTARGET_CREATE}
  	./make-print-version print_version.h
  
 +BUILD_OSTYPE!=  uname -s
 +.if ! empty(BUILD_OSTYPE:MCYGWIN*)
 +# Cygwin doesn't have arpa/nameser.h
 +_BINDDIR=${.CURDIR}/../../dist/bind
 +HOST_CPPFLAGS+=	-idirafter ${_BINDDIR}/lib/bind/include
 +HOST_CPPFLAGS+= -idirafter ${_BINDDIR}/lib/bind/port/cygwin/include
 +.endif
 +
  .include "${.CURDIR}/../Makefile.host"
  
  .PATH: ${DIST}/heimdal/lib/roken ${DIST}/heimdal/lib/vers
 Index: tools/host-mkdep/host-mkdep.in
 ===================================================================
 RCS file: /u0/cvsupbase/cvsroot-netbsd/src/tools/host-mkdep/host-mkdep.in,v
 retrieving revision 1.16
 diff -u -r1.16 host-mkdep.in
 --- tools/host-mkdep/host-mkdep.in	1 Sep 2005 21:51:11 -0000	1.16
 +++ tools/host-mkdep/host-mkdep.in	17 Apr 2007 22:49:29 -0000
 @@ -132,7 +132,7 @@
  				shift
  				;;
  
 -		-[IDU]|-include|-isystem)
 +		-[IDU]|-include|-isystem|-idirafter)
  				CPPFLAGS="$CPPFLAGS $1 $2"
  				shift 2
  				;;