Hi,
I have installed a recent libosmocore before I tried
to compile your testing branch.
Did you also do a fresh checkout or a "git clean -f -x -d" when
switching branch ?
Due to changes in the build system, residual from an old compilation
may prevent it from building.
In the mean
time you can find instructions to install libosmocore in
https://bs11-abis.gnumonks.org/trac/wiki/Building_OpenBSC
I try to read the instructions above, but I haven't access to the server because no
user and password.
Remove the 'https' ... it's only for authenticated wiki users.
Cheers,
Sylvain