doas: enable timestamp by default and set pamdir

* `--with-timestamp` enables the usage of the `persist` setting in
`doas.conf`. It is possible some people might not want this, so the flag
`withTimestamp` was added to control this.
* `--pamdir` copies the PAM files to `$out/etc/pam.d`. This may or may
not have a use in the future, but it removes a some errors from the
build (when it tries to copy these files to /etc/pam.d).

pkgs/tools/security/doas/default.nix

@@ -3,6 +3,8 @@
 , fetchFromGitHub
 , bison
 , pam
+
+, withTimestamp ? true
 }:
 
 stdenv.mkDerivation rec {
@@ -19,6 +21,11 @@ stdenv.mkDerivation rec {
   # otherwise confuses ./configure
   dontDisableStatic = true;
 
+  configureFlags = [
+    (lib.optionalString withTimestamp "--with-timestamp") # to allow the "persist" setting
+    "--pamdir=${placeholder "out"}/etc/pam.d"
+  ];
+
   postPatch = ''
     sed -i '/\(chown\|chmod\)/d' bsd.prog.mk
   '';