The makedefs file doesn't support Linux versions other than <=3. The build fails with: Unknown system type: Linux 4.0.0-rc5-JJ Reproducible: Always Steps to Reproduce: 1. use linux 4 2. emerge postfix 3. observe failure ;) quick fix patch is appended.
Created attachment 399838 [details, diff] fix the build for linux 4
Reported upstream: http://marc.info/?l=postfix-users&m=142744304401645&w=2
+*postfix-3.0.1-r1 (17 Apr 2015) + + 17 Apr 2015; Eray Aslan <eras@gentoo.org> +files/postfix-linux4.patch, + +postfix-3.0.1-r1.ebuild: + Fix building with linux-4 - bug #544610 +
*** Bug 550630 has been marked as a duplicate of this bug. ***
*** Bug 550684 has been marked as a duplicate of this bug. ***
*** Bug 550924 has been marked as a duplicate of this bug. ***