Warning: is_dir(): open_basedir restriction in effect
See https://github.com/civicrm/civicrm-core/pulls?q=basedir+is%3Aopen (saw a bunch of PRs as highlighted in the dev digest but no associated issue).
Happens with APIv3 Explorer (https://github.com/civicrm/civicrm-core/pull/21593), /CRM/Core/Smarty/plugins/ (https://github.com/civicrm/civicrm-core/pull/21589), etc.
When a server has open_basedir restrictions, error message logged repeatedly when using CiviCRM backend, especially with APIv3. PHP message: PHP Warning: is_dir(): open_basedir restriction in effect. File ... is not within the allowed path(s)
Also see #2795 - the solution should not simply suppress the errors.