[Help-bash] `set -v` difference in () vs not in ()

[Peng Yu]

Hi,

-v      Print shell input lines as they are read.

`set -v` behave differently whether it is in () or not. It seems that
is not documented. Why is it defined so?

$ cat ./main.sh
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

(
    set -v
    echo "Hello World!"
)

set -v
echo "Hello World!"
$ ./main.sh
Hello World!
echo "Hello World!"
Hello World!

-- 
Regards,
Peng