With this sequence of expressions FOOBAR = "a b c d" BAZBAR = "b d" FOOBAR_remove = "${BAZBAR}" bitbake -e shows that FOOBAR is "a b c d" The problem is when filtering from removesactive the values are expanded (so ${BAZBAR} becomes "b d") but this value isn't then split again.
Patch on the bitbake list.
Merge in bitbake 207013b6dde82f9654f9be996695c8335b95a288.