As reported by josteele, while http://download.jboss.org/jbosstools/neon/snapshots/builds/windup-eclipse-plugin-NIGHTLY/latest/all/repo/ is being updated correctly with each CI build, the composite site at its root is not.

Thus while http://download.jboss.org/jbosstools/neon/snapshots/builds/windup-eclipse-plugin-NIGHTLY/latest/all/repo/ points to build 141, http://download.jboss.org/jbosstools/neon/snapshots/builds/windup-eclipse-plugin-NIGHTLY/ points to builds 139 and 140, rather than 140 and 141.

Problem is likely either a server update lag, or a bug in https://github.com/jbosstools/jbosstools-build-ci/blob/jbosstools-4.4.x/util/cleanup/jbosstools-cleanup.sh#L230-L253