If I run oe-selftest without -j then the temporary [build dir]-st directory is not deleted: $ oe-selftest -r buildoptions.SourceMirroring.test_yocto_source_mirror 2020-06-23 11:18:31,074 - oe-selftest - INFO - Adding layer libraries: 2020-06-23 11:18:31,074 - oe-selftest - INFO - /home/ross/Yocto/poky/meta/lib 2020-06-23 11:18:31,075 - oe-selftest - INFO - /home/ross/Yocto/poky/meta-selftest/lib 2020-06-23 11:18:31,075 - oe-selftest - INFO - /home/ross/Yocto/poky/meta-yocto-bsp/lib 2020-06-23 11:18:31,078 - oe-selftest - INFO - Running bitbake -e to test the configuration is valid/parsable 2020-06-23 11:18:36,888 - oe-selftest - ERROR - Build directory /home/ross/Yocto/build-selftest-st already exists, aborting
http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=79856aaf934f27fd6ff781d9434c0889b4d93652