kselftest framework runs as build time or run time tests ?

HI team Quick question , does kselftest: https://kselftest.wiki.kernel.org/ Run on build time or run time ? I wonder because we want to implement it as part of our releases process ( which run on koji ) and honestly I don't want to run the tests against the kernel of the server , but on the kernel that we are building :) I ran it from the top directory of the kernel and as far as I can see is running on build time , just wanted to double check with you Best regards Victor Rodriguez