Installing sys-kernel/gentoo-kernel-6.1.22 sys-kernel/gentoo-kernel-6.1.12 with FEATURES=splitdebug LDFLAGS=-Wl,--build-id produces: * Detected file collision(s): * * /usr/lib/debug/.build-id/24/7bca5406f8a70ca36cc5412006c66055a1abf0.debug * /usr/lib/debug/.build-id/24/7bca5406f8a70ca36cc5412006c66055a1abf0 * /usr/lib/debug/.build-id/f4/f958c6ad8037cac41d784103e42ff7b0243d7b.debug * /usr/lib/debug/.build-id/f4/f958c6ad8037cac41d784103e42ff7b0243d7b * /usr/lib/debug/.build-id/fd/8fe111dd7f7e69fdec7c39dc4e9e11dc9aff1d * /usr/lib/debug/.build-id/fd/8fe111dd7f7e69fdec7c39dc4e9e11dc9aff1d.debug * * Searching all installed packages for file collisions... * * Press Ctrl-C to Stop * * sys-kernel/gentoo-kernel-6.1.12:6.1.12::gentoo * /usr/lib/debug/.build-id/24/7bca5406f8a70ca36cc5412006c66055a1abf0 * /usr/lib/debug/.build-id/24/7bca5406f8a70ca36cc5412006c66055a1abf0.debug * /usr/lib/debug/.build-id/f4/f958c6ad8037cac41d784103e42ff7b0243d7b * /usr/lib/debug/.build-id/f4/f958c6ad8037cac41d784103e42ff7b0243d7b.debug * /usr/lib/debug/.build-id/fd/8fe111dd7f7e69fdec7c39dc4e9e11dc9aff1d * /usr/lib/debug/.build-id/fd/8fe111dd7f7e69fdec7c39dc4e9e11dc9aff1d.debug ... this seems to be the case because these files didn't change between versions: ~$ diff /usr/src/linux-6.1.{12,22}-gentoo-dist-hardened/scripts/mod/modpost.c ~$