I followed the build instructions.
When I run: make
I get:
../vendor/leveldb-1.12.0/libleveldb.a(port_posix.cc.o): In function `leveldb::port::InitOnce(int*, void (*)())':
/home/tzadik/BitShares/vendor/leveldb-1.12.0/port/port_posix.cc:50: undefined reference to `pthread_once'