diff -r 21d3b40b4c0e -r 80840b651721 rust/rhg/src/commands/root.rs
--- a/rust/rhg/src/commands/root.rs	Fri Feb 12 16:54:30 2021 +0100
+++ b/rust/rhg/src/commands/root.rs	Mon Feb 15 20:05:32 2021 +0100
@@ -1,11 +1,7 @@
 use crate::error::CommandError;
-use crate::ui::Ui;
-use clap::ArgMatches;
 use format_bytes::format_bytes;
-use hg::config::Config;
 use hg::repo::Repo;
 use hg::utils::files::get_bytes_from_path;
-use std::path::Path;
 
 pub const HELP_TEXT: &str = "
 Print the root directory of the current repository.
@@ -17,14 +13,11 @@
     clap::SubCommand::with_name("root").about(HELP_TEXT)
 }
 
-pub fn run(
-    ui: &Ui,
-    config: &Config,
-    repo_path: Option<&Path>,
-    _args: &ArgMatches,
-) -> Result<(), CommandError> {
-    let repo = Repo::find(config, repo_path)?;
+pub fn run(invocation: &crate::CliInvocation) -> Result<(), CommandError> {
+    let repo = Repo::find(invocation.non_repo_config, invocation.repo_path)?;
     let bytes = get_bytes_from_path(repo.working_directory_path());
-    ui.write_stdout(&format_bytes!(b"{}\n", bytes.as_slice()))?;
+    invocation
+        .ui
+        .write_stdout(&format_bytes!(b"{}\n", bytes.as_slice()))?;
     Ok(())
 }