Portupgrade of rsync-2.5.5_1 fails with the following:

    rsync 2.5.6 configuration successful

===>  Building for rsync-2.5.6
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c rsync.c -o rsync.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c generator.c -o generator.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c receiver.c -o receiver.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c cleanup.c -o cleanup.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c sender.c -o sender.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c exclude.c -o exclude.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c util.c -o util.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c main.c -o main.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c checksum.c -o checksum.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c match.c -o match.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c syscall.c -o syscall.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c log.c -o log.o
log.c: In function `log_transfer':
log.c:579: warning: unused parameter `file'
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c backup.c -o backup.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c options.c -o options.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c flist.c -o flist.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c io.c -o io.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c compat.c -o compat.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c hlink.c -o hlink.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c token.c -o token.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c uidlist.c -o uidlist.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c socket.c -o socket.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c fileio.c -o fileio.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c batch.c -o batch.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c clientname.c -o clientname.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c progress.c -o progress.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c pipe.c -o pipe.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c params.c -o params.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c loadparm.c -o loadparm.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c clientserver.c -o clientserver.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c access.c -o access.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c connection.c -o connection.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c authenticate.c -o authenticate.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c lib/fnmatch.c -o lib/fnmatch.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c lib/compat.c -o lib/compat.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c lib/snprintf.c -o lib/snprintf.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c lib/mdfour.c -o lib/mdfour.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c lib/permstring.c -o lib/permstring.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/deflate.c -o zlib/deflate.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/infblock.c -o zlib/infblock.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/infcodes.c -o zlib/infcodes.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/inffast.c -o zlib/inffast.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/inflate.c -o zlib/inflate.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/inftrees.c -o zlib/inftrees.o
zlib/inftrees.c: In function `inflate_trees_fixed':
zlib/inftrees.c:403: warning: unused parameter `z'
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/infutil.c -o zlib/infutil.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/trees.c -o zlib/trees.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/zutil.c -o zlib/zutil.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c zlib/adler32.c -o zlib/adler32.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c popt/findme.c -o popt/findme.o
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c popt/popt.c -o popt/popt.o
popt/popt.c: In function `poptAddAlias':
popt/popt.c:1058: warning: unused parameter `flags'
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c popt/poptconfig.c -o popt/poptconfig.o
popt/poptconfig.c: In function `poptReadDefaultConfig':
popt/poptconfig.c:162: warning: unused parameter `useEnv'
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c popt/popthelp.c -o popt/popthelp.o
popt/popthelp.c: In function `displayArgs':
popt/popthelp.c:20: warning: unused parameter `foo'
popt/popthelp.c:22: warning: unused parameter `arg'
popt/popthelp.c:22: warning: unused parameter `data'
popt/popthelp.c: In function `getArgDescrip':
popt/popthelp.c:87: warning: unused parameter `translation_domain'
popt/popthelp.c: In function `singleOptionDefaultValue':
popt/popthelp.c:118: warning: unused parameter `translation_domain'
popt/popthelp.c: In function `poptPrintHelp':
popt/popthelp.c:478: warning: unused parameter `flags'
popt/popthelp.c: In function `poptPrintUsage':
popt/popthelp.c:637: warning: unused parameter `flags'
cc -I. -I. -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -c popt/poptparse.c -o popt/poptparse.o
cc -O -pipe -march=pentiumpro -DHAVE_CONFIG_H -Wall -W -I./popt  -o rsync rsync.o generator.o receiver.o cleanup.o sender.o exclude.o util.o  main.o checksum.o match.o syscall.o log.o backup.o options.o flist.o io.o compat.o hlink.o token.o uidlist.o socket.o  fileio.o batch.o clientname.o progress.o pipe.o params.o loadparm.o clientserver.o access.o connection.o authenticate.o lib/fnmatch.o lib/compat.o lib/snprintf.o lib/mdfour.o  lib/permstring.o zlib/deflate.o zlib/infblock.o zlib/infcodes.o zlib/inffast.o  zlib/inflate.o zlib/inftrees.o zlib/infutil.o zlib/trees.o  zlib/zutil.o zlib/adler32.o popt/findme.o  popt/popt.o  popt/poptconfig.o  popt/popthelp.o popt/poptparse.o 
--->  Backing up the old version
--->  Uninstalling the old version
--->  Deinstalling 'rsync-2.5.5_1'
[Updating the pkgdb <format:bdb1_btree> in /var/db/pkg ... - 219 packages found (-1 +0) (...) done]
--->  Installing the new version via the port
===>  Installing for rsync-2.5.6
mkdir -p /usr/local/bin
/usr/bin/install -c -o root -g wheel  -m 755 rsync /usr/local/bin
mkdir -p /usr/local/man/man1
mkdir -p /usr/local/man/man5
/usr/bin/install -c -o root -g wheel -m 644 ./rsync.1 /usr/local/man/man1
/usr/bin/install -c -o root -g wheel -m 644 ./rsyncd.conf.5 /usr/local/man/man5
===>   Generating temporary packing list
{STRIP_CMD}: not found
*** Error code 127

Stop in /usr/ports/net/rsync.
*** Error code 1

Stop in /usr/ports/net/rsync.
** Command failed [exit code 1]: /usr/bin/script -qa /tmp/portupgrade54161.0 make reinstall
egrep: /var/db/pkg/rsync-2.5.5_1/+CONTENTS: No such file or directory
--->  Restoring the old version
** Fix the installation problem and try again.
[Updating the pkgdb <format:bdb1_btree> in /var/db/pkg ... - 220 packages found (-0 +1) . done]
** The following packages were not installed or upgraded (*:skipped / !:failed)
	! net/rsync (rsync-2.5.5_1)	(install error)
#

Fix: 

Not sure.
How-To-Repeat: After fresh cvsup of ports tree, run:
portupgrade -R rsync-2.5.5_1