Libraries not found when using nightly

Dear List, I face the problem that when I am in general using the nightly builds on Ubuntu 20.04, but I want to compile a specific project (Osmo-BSC in this case), the configure script is not able to find the Osmocom libraries which are already installed and available. Output of the configure script: configure: error: Package requirements (libosmocore >= 1.8.0) were not met: Package 'libosmocore', required by 'virtual:world', not found Libosmocore is available on the system: root@openbsc:~/osmo-bsc_bootstrap_mod/osmo-bsc# ldconfig -v|grep libosmocore /sbin/ldconfig.real: Can't stat /usr/local/lib/i386-linux-gnu: No such file or directory /sbin/ldconfig.real: Path `/usr/lib/i386-linux-gnu' given more than once /sbin/ldconfig.real: Can't stat /usr/local/lib/i686-linux-gnu: No such file or directory /sbin/ldconfig.real: Can't stat /lib/i686-linux-gnu: No such file or directory /sbin/ldconfig.real: Can't stat /usr/lib/i686-linux-gnu: No such file or directory /sbin/ldconfig.real: Can't stat /usr/local/lib/x86_64-linux-gnu: No such file or directory /sbin/ldconfig.real: Path `/usr/lib/x86_64-linux-gnu' given more than once /sbin/ldconfig.real: Path `/lib/x86_64-linux-gnu' given more than once /sbin/ldconfig.real: Path `/usr/lib/x86_64-linux-gnu' given more than once /sbin/ldconfig.real: Path `/usr/lib' given more than once /sbin/ldconfig.real: /lib/i386-linux-gnu/ld-2.31.so is the dynamic linker, ignoring /sbin/ldconfig.real: /lib/x86_64-linux-gnu/ld-2.31.so is the dynamic linker, ignoring libosmocore.so.20 -> libosmocore.so.20.0.0 Can someone help me with what kind of flags do I need to provide to the configure script and how? Much appreciate the help! Regards, Csaba