The `server-init.sh` script calls `pidof rpc.idmapd` and therefore the
`pidof` command is needed in the server root file system.
--add-confdir test-root \
-a "bash $USE_NETWORK nfs" \
--add-drivers "nfsd sunrpc lockd" \
- -I "exportfs rpc.nfsd rpc.mountd dhcpd" \
+ -I "exportfs pidof rpc.nfsd rpc.mountd dhcpd" \
--install-optional "/etc/netconfig /etc/nsswitch.conf /etc/rpc /etc/protocols /etc/services /usr/etc/nsswitch.conf /usr/etc/rpc /usr/etc/protocols /usr/etc/services rpc.idmapd /etc/idmapd.conf" \
-i "./dhcpd.conf" "/etc/dhcpd.conf" \
-f "$TESTDIR"/initramfs.root