For SLE 12 SP5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ngncc/SLE_12_SP5/home:ngncc.repo
zypper refresh
zypper install lcov
For SLE 12 SP4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ngncc/SLE_12_SP4/home:ngncc.repo
zypper refresh
zypper install lcov
For SLE 12 SP3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ngncc/SLE_12_SP3/home:ngncc.repo
zypper refresh
zypper install lcov
For SLE 12 SP1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ngncc/SLE_12_SP1/home:ngncc.repo
zypper refresh
zypper install lcov