When configuring a regular expression to limit the set of allowed file systems during an item discovery I figured out that "/" in the regular expression causes problem.

To reproduce this effect create a regular expression of

^/$

and set it to

Result is TRUE

When trying to save the Zabbix frontend shows an error on the top:

preg_match(): Unknown modifier '$' [include/forms.inc.php:1753]

Apparently the "/" ends the regular expression and the "$" is considered a modifier to the expression.

The current workaround is to use ^\/$ instead of ^/$ (escaping the slash).
I would prefer though if the escaping would happen automatically.