build release fails : pbsdboot1.exe: stat: No such file or directory

Hi, from previous month to today I tried to build release
of the hpcmips port, but at the end of the build, it fails.

What is the cause of this problem?
I am running NetBSD/i386-current on WinXP SP2 VMware 6 WS,
and building i386-current release is successful.

Here's the build command:
time ./build.sh -x -j2 -m hpcmips -M ../obj/hpcmips -T ../tools/hpcmips
-D ../target/dest/hpcmips -R ../target/rel/hpcmips -u tools distribution 
sets
=> Succeeded.

However, the below fails.
time ./build.sh -x -j2 -m hpcmips -M ../obj/hpcmips -T ../tools/hpcmips
-D ../target/dest/hpcmips -R ../target/rel/hpcmips -u release

Below is the log of building release.

--------------

release ===> etc/hpcmips
--- check_RELEASEDIR ---
--- release ---
--- release ---
--- release ---
release ===> etc/hpcmips/cdroms
--- release ---
STRIP=/usr/export/NetBSD-build/src/../tools/hpcmips/bin/mipsel--netbsd-strip 
/usr/export/NetBSD-build/src/../tools/hpcmips/bin/nbinstall -r -p -c -m 
444 netbsd.gz netbsd-TX3912.gz netbsd.symbols.gz 
netbsd-TX3912.symbols.gz 
/usr/export/NetBSD-build/src/../target/rel/hpcmips/hpcmips/installation
--- release ---
--- release-installcd ---
release ===> etc/hpcmips/cdroms/installcd
STRIP=/usr/export/NetBSD-build/src/../tools/hpcmips/bin/mipsel--netbsd-strip 
/usr/export/NetBSD-build/src/../tools/hpcmips/bin/nbinstall -c -m 444 
pbsdboot1.exe 
/usr/export/NetBSD-build/src/../target/rel/hpcmips/hpcmips/installation
nbinstall: pbsdboot1.exe: stat: No such file or directory
*** [release] Error code 1
1 error

nbmake: stopped in /usr/export/NetBSD-build/src/distrib/hpcmips
*** [release-hpcmips] Error code 2
1 error

nbmake: stopped in /usr/export/NetBSD-build/src/distrib
*** [snap_post] Error code 2
1 error

nbmake: stopped in /usr/export/NetBSD-build/src/etc
*** [release] Error code 2
1 error

nbmake: stopped in /usr/export/NetBSD-build/src

ERROR: Failed to make release
*** BUILD ABORTED ***

Thanks
Ryo Chiba