Motivation for this change

I'm currently trying to set up a mail server (well, just a forwarder) with LDAP and Postfix. To this end, I've had to add support to the saslauthd service to NixOS, along with (optional, off-by-default) LDAP support.

I removed the --with-configdir to allow configs to be tucked in /etc/sasl2 along with the default location ($plugindir). This is necessary to allow configuring cyrus-sasl's behavior for some apps. For instance, I configure postfix's sasl2 with :

environment.etc."sasl2/smtpd.conf".text = ''
pwcheck_method: saslauthd
mech_list: PLAIN LOGIN
'';

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.