Some of the builds in Jenkins take big amounts of disk space (i.e: Gazebo classic 17Gb or ign-gazebo). The last build preserves the build/ directory in the workspace what makes Jenkins nodes to store large amounts of Gbs most of the times useless.

There is a IGN_CLEAN_WORKSPACE variable in Windows work that seems to do nothing. There is a KEEP_WS_FILES variable in ros builds that takes cares of removing build log directories in workspaces.

As an implementation detail: it would be great to code it as a post-build hook to run it even if the build failed.