Helix config.toml keymap that should perform two actions but takes two tries to get them both done

Question

I set this keymap on ./helix/config.toml :

[keys.normal]
backspace = {r = [":w", ":sh cargo run"]}

And when I first call the macro after doing a change in a rust file, it just executes the cargo run command, and only writes the new changes to the disk before running on the second time I do it.

I tried to set the keymap to save twice before the cargo run, but again it just made its work on the second attempt.