Log Message:
On some Linux systems with a sufficiently old sysutils/file installed,
we get this error, followed by a bunch of warnings attempting to compile
magic anyway:

"lt-file: Compiled magic version [540] does not match with shared library \ 
magic version [538]"

Instead of using whatever libmagic might already be installed, use the
just-built libmagic. (There's probably a less hacky way.)