Depending on the OVS version (in my case 2.4), you may find an error with ‘nroff’ python package during the compilation process. I fixed the problem by updating the ‘ovsdb-doc’ file.
$ cd ~/ovs/ovsdb $ wget https://raw.githubusercontent.com/openvswitch/ovs/master/ovsdb/ovsdb-doc
Probably, the file ‘debian/control’ might be missing.
Quick fix here.