How to send a package to CTAN with ctanupload? (I get an error)

How to send a package to CTAN with ctanupload? (I get an error)

Im trying to send a new package to CTAN and I wanted to use the makefile
given in the manual of ctanupload. This is how my file looks
CONTRIBUTION = metrix
NAME = Tobias Weh
EMAIL = mail@tweh.de
DIRECTORY = /macros/latex/contrib/${CONTRIBUTION}
LICENSE = free
FREEVERSION = lppl
FILE = ${CONTRIBUTION}.tar.gz
export CONTRIBUTION VERSION NAME EMAIL SUMMARY DIRECTORY DONOTANNOUNCE
ANNOUNCE NOTES LICENSE FREEVERSION FILE
ctanify: ${FILE}
${CONTRIBUTION}.sty: ${CONTRIBUTION}.ins ${CONTRIBUTION}.dtx
yes | tex $<
${FILE}: ${CONTRIBUTION}.dtx ${CONTRIBUTION}.ins ${CONTRIBUTION}.sty
README ${CONTRIBUTION}-doc.pdf
ctanify $^
upload: ctanify
ctanupload -p
Is saved this file as makefile in metrix/. I can run it with make and at
least ctanify produces the .tar.gz file but then nothing more happens.
When I try to call ctanupload -p directly from terminal I get this error:
Tobis-Mac:metrix Tobi$ ctanupload -p
Can't locate WWW/Mechanize.pm in @INC (@INC contains:
/Library/Perl/5.12/darwin-thread-multi-2level /Library/Perl/5.12
/Network/Library/Perl/5.12/darwin-thread-multi-2level
/Network/Library/Perl/5.12 /Library/Perl/Updates/5.12.4
/System/Library/Perl/5.12/darwin-thread-multi-2level
/System/Library/Perl/5.12
/System/Library/Perl/Extras/5.12/darwin-thread-multi-2level
/System/Library/Perl/Extras/5.12 .) at /usr/texbin/ctanupload line 434.
BEGIN failed--compilation aborted at /usr/texbin/ctanupload line 434.
Tobis-Mac:metrix Tobi$ ctanupload -p
Can't locate WWW/Mechanize.pm in @INC (@INC contains:
/Library/Perl/5.12/darwin-thread-multi-2level /Library/Perl/5.12
/Network/Library/Perl/5.12/darwin-thread-multi-2level
/Network/Library/Perl/5.12 /Library/Perl/Updates/5.12.4
/System/Library/Perl/5.12/darwin-thread-multi-2level
/System/Library/Perl/5.12
/System/Library/Perl/Extras/5.12/darwin-thread-multi-2level
/System/Library/Perl/Extras/5.12 .) at /usr/texbin/ctanupload line 434.
BEGIN failed--compilation aborted at /usr/texbin/ctanupload line 434.
I'm using Mac OS X 10.8 on a MacBook Pro. My TeX Live 2013 is as up to
date as possible. My Perl has the version number v5.12.4 (I can't find out
how to update …)