Better error logging when exec failed

xc-bin/src/main.rs

@@ -791,12 +791,17 @@ fn main() -> Result<(), ActionError> {
                 use_tty: terminal,
             };
 
-            if let Ok(response) = do_exec(&mut conn, request)? {
-                if let Some(socket) = response.terminal_socket {
-                    _ = attach::run(socket);
+            match do_exec(&mut conn, request)? {
+                Ok(response) => {
+                    if let Some(socket) = response.terminal_socket {
+                        _ = attach::run(socket);
+                    }
+                    let exit = n.notified_sync_take_value();
+                    std::process::exit((exit.unwrap_or(2) - 1) as i32)
+                },
+                Err(err) => {
+                    eprintln!("{err:?}")
                 }
-                let exit = n.notified_sync_take_value();
-                std::process::exit((exit.unwrap_or(2) - 1) as i32)
             }
         }
         Action::Volume(action) => {

xc/src/container/runner/mod.rs

@@ -381,13 +381,16 @@ impl ProcessRunner {
 
             match result {
                 Ok(spawn_info) => write_response(0, spawn_info).unwrap(),
-                Err(_err) => write_response(
-                    freebsd::libc::EIO,
-                    serde_json::json!({
-                        "message": "failed to spawn"
-                    }),
-                )
-                .unwrap(),
+                Err(err) => {
+                    error!("exec error: {err:?}");
+                    write_response(
+                        freebsd::libc::EIO,
+                        serde_json::json!({
+                            "message": format!("failed to spawn process in container: {err:?}")
+                        }),
+                    )
+                    .unwrap()
+                },
             }
         } else if method == "run_main" {
             if let Some(main) = self.container.main_proto.clone() {

xcd/src/site.rs

@@ -296,7 +296,7 @@ impl Site {
         if response.errno == 0 {
             Ok(serde_json::from_value(response.value).unwrap())
         } else {
-            ipc_err(freebsd::libc::EIO, "something went wrong")
+            ipc_err(freebsd::libc::EIO, &format!("something went wrong: {:?}", response.value))
         }
     }