Perhaps you know that your M2 executable is locate at
/foo/bar/bin/M2, say, but when you run it, you get something like this:
/foo/bar/bin/M2
M2: error while loading shared libraries: liblapack.so: cannot open shared object file: No such file or directory
What that means is that M2 hasn't been told where its shared libraries are. Actually, it's the operating system that has to be told, since otherwise M2 can't even start up. Hopefully, the missing shared libraries are located in
/foo/bar/lib, and all we have to do is to tell the operating system by setting the environment variable
LD_LIBRARY_PATH.
Alternatively, you may be getting something like this:
$ /foo/bar/bin/M2
dyld: Library not loaded: /capybara/lib/libgmp.3.dylib
Referenced from: /foo/bar/bin/M2
Reason: image not found
Trace/BPT trap
That would mean that you are running under MacOS, and the instructions here may not apply.
The simplest way to teach your operating system how to find M2's shared libraries is to let M2 do it for you. Assuming that M2 is located at
/foo/bar/bin/M2, run the following command:
/foo/bar/bin/M2-load-libs
and then, in response to Macaulay2's input prompt, enter
setup(). If that works, the next time you log in or start a new shell, the operating system should know how to find M2's shared libraries, and running
/foo/bar/bin/M2 should work, and you can move on to the next step.