libc.so.6: ELF file OS ABI invalid

[David Banning]

I get this error when I attempt to run acroread8;

/compat/linux/bin/sh: error while loading shared libraries: /usr/local/lib/libc.so.6: ELF file OS ABI invalid

I get the impression maybe acroread is attempting run a linux binary
using a freebsd library - but I am not sure if this is so, or how to fix
it. Any pointers would be appreciated.