Output error messages when using `execute` from vpype API about vpype HOT 4 OPEN

try:
    doc = vp.execute_throw("....", doc)
except Exception:
   pass # handle error here

import contextlib
import io

import vpype_cli

try:
    output = io.StringIO()
    with contextlib.redirect_stdout(output):
        vpype_cli.execute("read doesntexist.svg show", global_opt="-vv")
    print("Output")
    print(output.getvalue())
except Exception as e:
    print("Error:")
    print(type(e))
    print(e)