Jeff
  Here's a log of what happens when I build from current CVS sources on 
Windows XP x64, with the cygwin based build.

First, note that I'm using the 64-bit compiler:

Administrator@honolulu /cygdrive/j/tclcvs/tcl/win
$ which cl
/cygdrive/c/Program Files (x86)/Microsoft Visual Studio 8\VC\bin\amd64/cl

Administrator@honolulu /cygdrive/j/tclcvs/tcl/win
$ cl
Microsoft (R) C/C++ Optimizing Compiler Version 14.00.50727.42 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

usage: cl [ option... ] filename... [ /link linkoption... ]


Here's the actual build log:

Administrator@honolulu /cygdrive/j/tclcvs/tcl/win
$ ./configure
checking for gcc... no
checking for cc... no
checking for cc... no
checking for cl... cl
checking for C compiler default output file name... conftest.exe
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables... .exe
checking for suffix of object files... obj
checking whether we are using the GNU C compiler... no
checking whether cl accepts -g... yes
checking for cl option to accept ANSI C... none needed
checking whether make sets $(MAKE)... yes
checking for Cygwin version of gcc... no
checking for SEH support in compiler... yes
checking for EXCEPTION_DISPOSITION support in include files... yes
checking for LPFN_ACCEPT support in winsock2.h... no
checking for winnt.h that ignores VOID define... no
checking for alloca declaration in malloc.h... yes
checking for cast to union support... no
checking for FINDEX_INFO_LEVELS in winbase.h... no
checking for MWMO_ALERTABLE in winuser.h... yes
checking for building with threads... no (default)
checking how to build libraries... shared
checking if 64bit support is requested... no
checking if Windows/CE build is requested... no
checking for Windows/CE celib directory... NO_CELIB
checking for cygpath... cygpath -w
checking compiler flags... using shared flags
checking for build with symbols... no
configure: creating ./config.status
config.status: creating Makefile
config.status: creating tclConfig.sh
config.status: creating tcl.hpj

Administrator@honolulu /cygdrive/j/tclcvs/tcl/win
$ ls
CVS              config.status  tcl.dsw          tclWinDde.c     tclWinSerial.c
Makefile         configure      tcl.hpj          tclWinError.c   tclWinSock.c
Makefile.in      configure.in   tcl.hpj.in       tclWinFCmd.c    tclWinTest.c
README           makefile.bc    tcl.m4           tclWinFile.c    tclWinThrd.c
README.binary    makefile.vc    tcl.rc           tclWinInit.c    tclWinThrd.h
Release          nmakehlp.c     tclAppInit.c     tclWinInt.h     tclWinTime.c
aclocal.m4       nmakehlp.exe   tclConfig.sh     tclWinLoad.c    tclsh.ico
buildall.vc.bat  nmakehlp.obj   tclConfig.sh.in  tclWinNotify.c  tclsh.rc
cat.c            rules.vc       tclWin32Dll.c    tclWinPipe.c
coffbase.txt     stub16.c       tclWinChan.c     tclWinPort.h
config.log       tcl.dsp        tclWinConsole.c  tclWinReg.c

Administrator@honolulu /cygdrive/j/tclcvs/tcl/win
$ make
cl -c -nologo -O2 -MD -W3  -I"j:\tclcvs\tcl\generic" -DTCL_TOMMATH -DMP_PREC=4 -I"j:\tclcvs\tcl\libtommath" -I".\" -DPACKAGE_NAME=\"\" -DPACKAGE_TARNAME=\"\" -DPACKAGE_VERSION=\"\" -DPACKAGE_STRING=\"\" -DPACKAGE_BUGREPORT=\"\" -DHAVE_NO_LPFN_DECLS=1 -DHAVE_NO_FINDEX_ENUMS=1 -DTCL_CFGVAL_ENCODING=\"cp1252\" -DTCL_CFG_OPTIMIZED=1 -DTCL_CFG_DEBUG=1   -DBUILD_tcl "j:\tclcvs\tcl\generic\regcomp.c" -Foregcomp.obj
/bin/sh: -c: line 0: unexpected EOF while looking for matching `"'
/bin/sh: -c: line 1: syntax error: unexpected end of file
make: *** [regcomp.obj] Error 2


Administrator@honolulu /cygdrive/j/tclcvs/tcl/win