[build2] No compiler output when {}-imbalance detected

[Markus Pawellek]

Hello,

if build2 detects a {}-imbalance, one only gets an error message from
build2 itself and not from the compiler.
But build2 gives us no clue where exactly an opening or closing brace
is missing.
The compiler error message is much more descriptive and tells us
something about the position where the brace could have been
forgotten.
Is there a way to somehow show the actual output of the compiler in
this scenario?
Thank you in advance.

Greetings
Markus