Anyone built RXTX for Yun?

It is strange that they ended up there, I think that location will be where your virtual machine libraries go.

Run file on one of the libraries, here is what I get on libglib for the Yun:

file staging_dir/target-mips_r2_uClibc-0.9.33.2/lib/libudev.so.0.12.0 
staging_dir/target-mips_r2_uClibc-0.9.33.2/lib/libudev.so.0.12.0: ELF 32-bit MSB shared object, MIPS, MIPS32 rel2 version 1 (SYSV), dynamically linked, with unknown capability 0x41000000 = 0xf676e75, with unknown capability 0x10000 = 0x70403, not stripped

Here is what I get for a libudev for my desktop:

file /lib/i386-linux-gnu/libudev.so.1.3.5 
/lib/i386-linux-gnu/libudev.so.1.3.5: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, BuildID[sha1]=0x90e1b857dd268065195c5aadd9abe6b59600a368, stripped

The part you are looking for is the processor it should be MIPS for a Yun library