I tried several times to get this library (libmp3lame.dylib) for mp3 exporting. I couldn’t find it on the recommended download link: http://lame.buanzo.org/
I installed via dmg and zip, but it was no where to be found. Finally found it on this site: http://spaghetticode.org/lame/
It says it is for Audacity 1.2.6, but it seems to work for 2.1.1
We do not recommend downloading Audacity or Lame from websites other than those given in the official documentation. We are do not have the time to check the validity or safety of downloads from other sources, and are therefore not able to offer technical support for unofficial downloads. The maintainer of the http://lame.buanzo.org/ website is happy to provide support in the event of difficulties downloading from his site, and we are happy to help in the event of difficulties downloading Audacity from http://web.audacityteam.org/download/ Downloading from other sources is at your own risk.
Strange site. No frontpage and Lame is the only thing on the site. It’s 3 years old and it looks like there hasn’t been anything done on the site since.
There are sites online you can check to see if a page is really down for everyone, or if there is some problem just for you. For example http://downforeveryoneorjustme.com/.