Folder structure for nightlybuilds

The error is "undefined symbol", so probably one of the shared library, on which mscore depends, installed in your system is too old (just a wild guess). If the library was not found, I would have expected instead an error on opening mscore.
You can try to type in a terminal:
ldd ./mscore
to see the library upon which mscore depends and if it found evrything in your system.

I think the nightly builds in linux (are you using 32bits or 64bits?) are built upon Qt5.2.0, so you can try to check if your Qt is 5.2.0.
If you are missing libraries or the right version of them, you can try to download such required libraries and install, or put them in a folder and then add it to the environment variable LD_LIBRARY_PATH before launching mscore. For example, to run the nightly builds, I found that I had to add Qt 5.2.0 library folder to LD_LIBRARY_PATH. Then I discovered that (64bits) nightly builds require libc at version 2.16, while I have the 2.15 installed: I will try next week to download libc 2.16 and see if afterwards I can run the nightly builds.

You can also try to build mscore by yourself: just follow the instruction in the Development handbook.

Hope this help.

Ciao,
ABL