problem building R 2.12.1 64-bit on Windows 7

Hello,

I am stuck trying to build 64-bit R 2.12.1 on Windows 7, hopefully the
problem is obvious and someone can point out what I'm missing.

Well into the "make all recommended" process, I get an error:

make[4]: *** [Rzlib.dll] Error 4

(A longer report on the error in the build print is below - there
is also help output from sed that I have included but don't know if it
is relevant. )

If I follow the same set up but choose a 32-bit build it runs
successfully to completion and I can run R.

I have tried this on two different machines running 64-bit Windows
with the released R 2.12.1. The error is the same when using
R-patched_2010-12-27_r53886.

I'm sorry if this is something obvious, but I believe I've followed
the instructions carefully and do not know what I might be doing
wrong.

As far as I can tell I should not need to modify BINPREF64 or SYMPAT64
if use Rtools 2.12. Is that correct?

A description of the set up and build process follows.

Best regards, Mike.


----------------------------------
Context
----------------------------------

Using Rtools212.exe, with MiKTeX, no static HTML help, and no
installer build.

Everything installed is Run As Administrator, including the command
prompt used to build R.

-----------------------------------
Environment Variables
-----------------------------------

These environment variables are set:

PATH

Rtools and MiKTeX installed, with the following at the start of PATH:

c:\inst\R\Rtools\bin;c:\inst\R\Rtools\perl\bin;c:\inst\R\Rtools\MinGW\bin;c:\inst\R\Rtools\MinGW64\bin;C:\inst\MiKTeX\miktex\bin;

TAR_OPTIONS

Options to avoid messages when extracting sources:

--no-same-owner --no-same-permissions

TMPDIR

I can write to this directory:

G:\systemTEMP

--------------------------------
Build steps
--------------------------------

1) Extract from the archive

tar -xf R-patched_2010-12-27_r53886.tar.gz

2) Copy Rsrc "src/" and "Tcl/" into R-patched/ from the relevant 64
bit Rtools source

3) Create the following file [R_HOME]/src/gnuwin32/MkRules.local

# 32- or 64-bit Windows?
WIN = 64

JPEGDIR = jpeg-8a

4) Make

cd R-patched/src/gnuwin32
make all recommended


---------------------------------
Error message in context
---------------------------------
. . .
making uncompr.d from uncompr.c
making zutil.d from zutil.c
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c adler32.c -o adler32.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c compress.c -o compress.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c crc32.c -o crc32.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c deflate.c -o deflate.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c gzio.c -o gzio.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c infback.c -o infback.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c inffast.c -o inffast.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c inflate.c -o inflate.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c inftrees.c -o inftrees.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c trees.c -o trees.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c uncompr.c -o uncompr.o
gcc -std=gnu99   -I../../include -DHAVE_CONFIG_H -O3 -Wall -pedantic
-DR_ARCH='"x64"' -DW64 -c zutil.c -o zutil.o
Usage: sed [OPTION]... {script-only-if-no-other-script} [input-file]...

   -n, --quiet, --silent
                  suppress automatic printing of pattern space
   -e script, --expression=script
                  add the script to the commands to be executed
   -f script-file, --file=script-file
                  add the contents of script-file to the commands to be executed
   --follow-symlinks
                  follow symlinks when processing in place
   -i[SUFFIX], --in-place[=SUFFIX]
                  edit files in place (makes backup if extension supplied)
   -b, --binary
                  open files in binary mode (CR+LFs are not processed specially)
   -l N, --line-length=N
                  specify the desired line-wrap length for the `l' command
   --posix
                  disable all GNU extensions.
   -r, --regexp-extended
                  use extended regular expressions in the script.
   -s, --separate
                  consider files as separate rather than as a single continuous
                  long stream.
   -u, --unbuffered
                  load minimal amounts of data from the input files and flush
                  the output buffers more often
       --help     display this help and exit
       --version  output version information and exit

If no -e, --expression, -f, or --file option is given, then the first
non-option argument is taken as the sed script to interpret.  All
remaining arguments are names of input files; if no input files are
specified, then the standard input is read.

GNU sed home page:<http://www.gnu.org/software/sed/>.
General help using GNU software:<http://www.gnu.org/gethelp/>.
make[4]: *** [Rzlib.dll] Error 4
make[3]: *** [rlibs] Error 1
make[2]: *** [../../bin/x64/R.dll] Error 2
make[1]: *** [rbuild] Error 2
make: *** [all] Error 2