feat(cli): improve error reporting when cannot run cargo

tools/cli/src/utils.rs

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+use std::fmt::Formatter;
+use std::io::ErrorKind;
 use std::process::Command;
 use std::process::Stdio;
 
@@ -32,13 +34,48 @@ fn run_command<T: Into<Stdio>>(
     mut command: Command,
     stdout_config: T,
 ) -> Result<String, anyhow::Error> {
-    let process = command.stdout(stdout_config).spawn()?;
+    let process = command
+        .stdout(stdout_config)
+        .spawn()
+        .map_err(|e| process_command_run_error(e, &command))?;
 
     let output = process.wait_with_output()?;
     if !output.status.success() {
-        anyhow::bail!("failed to execute, exited with {}", output.status)
+        anyhow::bail!(
+            r#"command `{}` exited with {}"#,
+            PrintCommand(&command),
+            output.status
+        )
     }
 
     let stdout = String::from_utf8_lossy(&output.stdout).into_owned();
     Ok(stdout)
 }
+
+struct PrintCommand<'c>(&'c Command);
+
+impl<'c> std::fmt::Display for PrintCommand<'c> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0.get_program().to_string_lossy())?;
+        for arg in self.0.get_args() {
+            write!(f, " {}", arg.to_string_lossy())?;
+        }
+
+        Ok(())
+    }
+}
+
+fn process_command_run_error(e: std::io::Error, command: &Command) -> anyhow::Error {
+    if e.kind() == ErrorKind::NotFound {
+        anyhow::anyhow!(
+            r#"cannot run `{}`: executable not found in $PATH"#,
+            command.get_program().to_string_lossy(),
+        )
+    } else {
+        anyhow::anyhow!(
+            r#"cannot run `{}`: {}"#,
+            command.get_program().to_string_lossy(),
+            e
+        )
+    }
+}