configure:15174: checking for nss-config
configure:15209: checking for NSS - version >= 3.15.4
configure: error: you don't have NSS installed or your version is too old
*** Fix above errors and then restart with\
               "make -f client.mk build"
/usr/ports/opt/firefox/work/src/mozilla-release/client.mk:363: recipe for target
 'configure' failed
make[2]: *** [configure] Error 1
make[2]: Leaving directory '/usr/ports/opt/firefox/work/src/mozilla-release'
/usr/ports/opt/firefox/work/src/mozilla-release/client.mk:377: recipe for target
 '/usr/ports/opt/firefox/work/src/mozilla-release/firefox-shared/Makefile' faile
d
make[1]: *** [/usr/ports/opt/firefox/work/src/mozilla-release/firefox-shared/Mak
efile] Error 2
make[1]: Leaving directory '/usr/ports/opt/firefox/work/src/mozilla-release'
client.mk:185: recipe for target 'build' failed
make: *** [build] Error 2
=======> ERROR: Building '/usr/ports/opt/firefox/firefox#28.0-1.pkg.tar.gz' fail
ed.