Comment 8 for bug 839130

I recompiled xul-ext-lightning after adding ‘Breaks: ${xpi:Breaks}’ to all its debian/control stanzas, and ended up with what appears to be the right thing. The result installs and works.

Package: xul-ext-lightning
Provides: imap-client, mail-reader, seamonkey-lightning, thunderbird-lightning
Depends: xul-ext-calendar-timezones, libc6 (>= 2.7), libnspr4 (>= 4.7.3-0ubuntu1~), libstdc++6 (>= 4.1.1)
Recommends: thunderbird (>= 7.0~a1) | seamonkey (>= 2.4~a1), xul-ext-gdata-provider
Suggests: latex-xft-fonts
Breaks: seamonkey (>= 2.4.+), seamonkey (<< 2.4~a1), thunderbird (>= 7.+), thunderbird (<< 7.0~a1)
Enhances: seamonkey, thunderbird