Just answering my own question to confirm that the toolchain script also can be moved to a small medium like a live cd and compile osmocom-bb. First remove the src and build directories that are inside the folder from where the osmocom-bb toolchain script was run, here called dublin and then:

cp -rp /root/dublin/install  /root/copyfolder

tar cf name.tar copyfolder  && bzip2 name.tar

Then copy name.tar.bz2 onto the live-cd and unpack it. Then

mv copyfolder dublin

The compilation errors disappeared after doing
export LD_LIBRARY_PATH=/usr/local/lib and installing libmpc-dev

Regards
//erich