lower MSRV to 1.57.0

This line uses the Display trait for io::ErrorKind which was stabilized
in Rust 1.60.0. We can set MSRV all the way back to 1.57.0 by replacing
it with a pretty-print.

Closes helix-editor#2460

helix-term/Cargo.toml

@@ -10,7 +10,7 @@ repository = "https://github.com/helix-editor/helix"
 homepage = "https://helix-editor.com"
 include = ["src/**/*", "README.md"]
 default-run = "hx"
-metadata.msrv = "1.60.0"
+metadata.msrv = "1.57.0"
 
 [package.metadata.nix]
 build = true

helix-view/src/handlers/dap.rs

@@ -302,7 +302,9 @@ impl Editor {
                                     .arg(arguments.args.join(" "))
                                     .spawn()
                                     .unwrap(),
-                                e => panic!("Error to start debug console: {}", e),
+                                // TODO replace pretty-print with standard format when MSRV
+                                // is raised to 1.60.0
+                                e => panic!("Error to start debug console: {:?}", e),
                             })
                     } else {
                         std::process::Command::new("tmux")