downgrade to latest 3.x version of clap

src/args.rs

@@ -2,8 +2,8 @@ use clap::{Arg, Command};
 
 use crate::action::*;
 
-fn get_arg_parser() -> Command {
-    Command::new("pacdef")
+fn get_arg_parser() -> Command<'static> {
+    let result = Command::new("pacdef")
         .about("declarative package manager for Arch Linux")
         .version("1.0.0-alpha")
         .subcommand_required(true)
@@ -13,7 +13,7 @@ fn get_arg_parser() -> Command {
             Command::new(EDIT)
                 .about("edit one or more existing group files")
                 .arg_required_else_help(true)
-                .arg(Arg::new("group").num_args(0..)),
+                .arg(Arg::new("group").multiple_values(true)),
         )
         .subcommand(Command::new(GROUPS).about("show names of imported groups"))
         .subcommand(Command::new(SYNC).about("install packages from all imported groups"))
@@ -21,7 +21,8 @@ fn get_arg_parser() -> Command {
             Command::new(UNMANAGED)
                 .about("show explicitly installed packages not managed by pacdef"),
         )
-        .subcommand(Command::new(VERSION).about("show version info"))
+        .subcommand(Command::new(VERSION).about("show version info"));
+    result
 }
 
 pub fn get_args() -> clap::ArgMatches {