ifenslave-2.6_1.1.0-13.diff.gz is no longer available on any debian servers. So in ebuild ifenslave-1.1.0-r5.ebuild DEBIAN_PV="13" should be corrected to DEBIAN_PV="10" (or better to 17, but I cannot find 17 diff). Reproducible: Always
This has been fixed in ifenslave-1.1.0-r6. Thanks!