severity: error
S = "${WORKDIR}"
or
B = "${WORKDIR}/foo/bar"
Recently upstream changed the way sources are unpacked/refreshed on changes of the SRC_URI inputs. Unpacking in WORKDIR makes it impossible to determine what is a new resource and what might be a left-over from a previous run. Hence UNPACKDIR was introduced - users should refrain from using WORKDIR for S or B
S = "${UNPACKDIR}"
or
B = "${UNPACKDIR}/foo/bar"