tempest-lib is removed upstream long time back in favour of tempest.lib api. Once an user upgrades the package to Queens, It can create conflicts. so it is better to obselete the package if already available on the environment. Here is the review queue for the same in rdo: https://review.rdoproject.org/r/#/q/topic:obseletes_tempest_lib
unused and now dropped from OSP 13
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2018:2086