notmuch: add programs.notmuch.package option

Allow users to specify which notmuch package should be used.

(cherry picked from commit 9bdb693810)

modules/programs/git.nix

@@ -379,7 +379,7 @@ in
               lib.nameValuePair "sendemail.${name}" (
                 if account.msmtp.enable then
                   {
-                    sendmailCmd = "${pkgs.msmtp}/bin/msmtp";
+                    sendmailCmd = lib.getExe config.programs.msmtp.package;
                     envelopeSender = "auto";
                     from = "${realName} <${address}>";
                   }

modules/programs/notmuch/default.nix

@@ -72,6 +72,8 @@ in
     programs.notmuch = {
       enable = lib.mkEnableOption "Notmuch mail indexer";
 
+      package = lib.mkPackageOption pkgs "notmuch" { };
+
       new = mkOption {
         type = types.submodule {
           options = {
@@ -197,7 +199,7 @@ in
       }
     ];
 
-    home.packages = [ pkgs.notmuch ];
+    home.packages = [ cfg.package ];
 
     home.sessionVariables = {
       NOTMUCH_CONFIG = "${config.xdg.configHome}/notmuch/default/config";
@@ -208,7 +210,7 @@ in
       let
         hook = name: cmds: {
           "notmuch/default/hooks/${name}".source = pkgs.writeShellScript name ''
-            export PATH="${pkgs.notmuch}/bin''${PATH:+:}$PATH"
+            export PATH="${cfg.package}/bin''${PATH:+:}$PATH"
             export NOTMUCH_CONFIG="${config.xdg.configHome}/notmuch/default/config"
             export NMBGIT="${config.xdg.dataHome}/notmuch/nmbug"