Search for manpages
Either install with make install or if you wish to choose your own location make BINDIR=<dir> install or just move it to a directory yourself.
mansearch <search term>$ mansearch namespace
/usr/share/man/man7/cgroup_namespaces.7.bz2
/usr/share/man/man7/gitnamespaces.7.bz2
/usr/share/man/man7/ipc_namespaces.7.bz2
/usr/share/man/man7/mount_namespaces.7.bz2
/usr/share/man/man7/namespaces.7.bz2
/usr/share/man/man7/network_namespaces.7.bz2
/usr/share/man/man7/pid_namespaces.7.bz2
/usr/share/man/man7/time_namespaces.7.bz2
/usr/share/man/man7/user_namespaces.7.bz2
/usr/share/man/man7/uts_namespaces.7.bz2
/usr/share/man/mann/namespace.n.bz2