OSS Core Library build environment is influenced by sipXecs build setup.
To list build dependencies
grep '^BuildRequires' oss_core/oss_core.spec.in | awk '{print $2}'
To list runtime dependencies
grep '^Requires' oss_core/oss_core.spec.in | awk '{print $2}'
Download the source code from https://github.com/joegen/oss_core and build it
git clone https://github.com/joegen/oss_core.git
cd oss_core
git submodule init
git submoule update
autoreconf -if
mkdir -p .build
cd .build
../configure
echo "%_topdir $HOME/rpmbuild" >> ~/.rpmmacros
mkdir -p ~/rpmbuild/{BUILD,SOURCES,RPMS,SRPMS,SPECS}
cd oss_core
autoreconf -if
mkdir -p .build
cd .build
../configure
make dist
rpmbuild -ta oss_core-*tar.gz