In the case of Uganda and Djibouti, both parties to the Rome Statute, the ICC passed an internal ruling judging that both states failed to uphold international law by refusing to arrest Al Bashir when he visited those countries in 2015 and 2016. This document outlines the "ruling" against Djibouti.
What does the ICC do in the case of violators like Djibouti? Refer the case to the United Nations Security Council.
https://www.icc-cpi.int/sites/default/files/CourtRecords/CR2016_04946.PDF