I just ran `set -x` and got a bunch of crazy output:

```
echo hello
+_zsh_highlight_preexec_hook:2> _ZSH_HIGHLIGHT_PRIOR_BUFFER='' 
+_zsh_highlight_preexec_hook:3> _ZSH_HIGHLIGHT_PRIOR_CURSOR='' 
+-zsh:348> echo hello
hello
+precmd:0> vcs_info prompt 
+....etc
```

Maybe `set -v` is better? Check it:

```
$ set -v
$ echo hello
echo hello
hello
```