Created attachment 490054 [details] builld.log In its current state, it looks like udisks-2.7.2 uses the USE=crypt features of libblockdev unconditionally.
Created attachment 490056 [details] corresponding config.log
For good measure-- Builds fine against: [ebuild R ] sys-libs/libblockdev-2.11::gentoo USE="crypt -bcache -dmraid -doc -kbd -lvm -python {-test}" PYTHON_SINGLE_TARGET="python3_5 -python3_4 -python3_6" PYTHON_TARGETS="python3_5 -python3_4 -python3_6" 0 KiB But shows the aforementioned failure against: [ebuild R ] sys-libs/libblockdev-2.11::gentoo USE="-bcache -crypt -dmraid -doc -kbd -lvm -python {-test}" PYTHON_SINGLE_TARGET="python3_5 -python3_4 -python3_6" PYTHON_TARGETS="python3_5 -python3_4 -python3_6" 0 KiB
commit b28fdac805f7f62b1671769a5a7eb8d0e4bfe646 Author: Lars Wendler <polynomial-c@gentoo.org> Date: Fri Sep 1 22:51:24 2017 sys-fs/udisks: Depend on libblockdev[crypt] unconditionally (bug #628612). Package-Manager: Portage-2.3.8, Repoman-2.3.3