Arch Linux

The exim compile time options are being set by an ugly pipe-hackery of incremental sed commands, each modifying the output of the previous one. This is an ugly, unreadable hack and effectively prevents users from being able to read which options are actually applied and available. I suggest to include a modified copy of src/EDITME alongside with the PKGBUILD and copy it to Local/Makefile at the beginning of build() so the local sysadmin can make modifications to that file and recompile exim with compile-time-options which fit their needs. The EDITME file is supposed to be edited by whoever wants to change exim options.

Quoting src/EDITME:
This is the template for Exim's main build-time configuration file. It contains settings that are independent of any operating system. These are things that are mostly sysadmin choices. The items below are divided into those you must specify, those you probably want to specify, those you might often want to specify, and those that you almost never need to mention.

This would make it more convenient to rebuild exim with additional database backends, like for instance LOOKUP_PGSQL, without having to make the official exim package depend on something only a minority of the users use.