meta/lib/oeqa/selftest/cases/runtime_test.py has hardcoded references to "/tmp/sdk". This races, for example: https://autobuilder.yoctoproject.org/typhoon/#/builders/56/builds/1484 where an oe-selftest and oe-selftest-centos ran on the same system and one broke the other. The fix is not to use hardcoded paths in the test.
http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=cb7996ae212372fc7e03fdf710dae6e0f1876344