[Mac OS X] MuseScore can't open LAME library for MP3 export
(This is a more precise issue posting for #42331: Error: Could not open MP3 encoding library!).
So! I'm going to be as specific as possible about each step of the process I'm going through, to try to eliminate any ambiguity. For this test, I'm using a 2009 MacBook running Mac OS X 10.9.5.
I started by booting into my Mac's recovery partition and repairing my startup disk, just because people were telling me there must be something wrong with my installation. This task accomplished, I rebooted and deleted my current installation of the LAME MP3 library from my computer. I then downloaded it afresh (version 3.98.2) from http://lame.buanzo.org/#lameosxdl and, in this case, used the ZIP archive. (In previous tests I have used the Installer package which, according to Pacifist, places the .dylib in /usr/local/lib/audacity. This, however, is a folder that requires root permissions to even see into, which I do not have enabled. In order to be sure I know the library is there, I chose to extract the archive and leave it in ~/Downloads/Lame_Library_v3.98.2_for_Audacity_on_OSX.)
At the same time, I downloaded the latest MuseScore nightly build (2015-02-06-2202-b9e10df), replaced the slightly older version in my /Applications folder, and from the Terminal ran
/Applications/MuseScoreNightly.app/Contents/MacOS/mscore -F, quitting the nightly to complete the process.
Everything's set to go. I relaunch MuseScoreNightly and just use the My_First_Score that automatically opens. I enter a few notes, go to the File menu and choose Export… . Up comes the window where I can choose what format and what location I want to save to. I go with the default location and choose "MP3 Audio (*.mp3)" from the dropdown menu as my file format.
A dialog appears:
I click "Yes."
Exactly as with Audacity, the window appears where you can browse or search for libmp3lame.dylib. Once it's found and selected, I click "Open." (Note: I'm not posting a screenshot of this because personal information would be visible.)
And then we hit a dead end.