For openSUSE Leap 15.2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:szotsaki/openSUSE_Leap_15.2/home:szotsaki.repo
zypper refresh
zypper install kashmir-devel
For openSUSE Leap 15.1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:szotsaki/openSUSE_Leap_15.1/home:szotsaki.repo
zypper refresh
zypper install kashmir-devel
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:szotsaki/15.4/home:szotsaki.repo
zypper refresh
zypper install kashmir-devel
For 15.3 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:szotsaki/15.3/home:szotsaki.repo
zypper refresh
zypper install kashmir-devel