The file system partition of the core benchmarks runner is full

$ df -h /dev/sda2
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2       117G  111G     0 100% /

This happened because the influx database is struggling to keep up. The runner sees a timeout exception when trying to upload results. It decides to keep the build directory, because that might be useful to have in case of errors. The accumulated build directories quickly fills up the remaining space of the device.