Upgrade to the latest upstream release (current 2.0.6), compatible with Firefox 33 and later. Port www/xpi-firebug 2.0.3 doesn't work with Firefox 34.
Auto-assigned to maintainer bar@FreeBSD.org
A commit references this bug: Author: bar Date: Mon Dec 8 00:20:11 UTC 2014 New revision: 374229 URL: https://svnweb.freebsd.org/changeset/ports/374229 Log: Update firebug to 2.0.6. PR: 195735 Changes: head/www/xpi-firebug/Makefile head/www/xpi-firebug/distinfo head/www/xpi-firebug/pkg-plist