7.3.1 corruption issue

I can't file a bug report because I do not know what went run. I only
know system

php 7.3.1

Site suddenly stopped working.
Apache error log says:

Mon Jan 28 00:45:17.896727 2019] [php7:error] [pid 4117:tid
140287279617792] [client 73.15.182.232:53028] PHP Fatal error:
require_once(): Failed opening required 'base.inc.php'
(include_path='.:/usr/share/pear:/usr/share/php') in
/srv/[redacted]/www/controller.php on line 2

That include path is interesting, it lists /usr/share/pear:/usr/share/php

I set the include path in Apache config:

<Directory "/srv/[redacted]/www">
  Options FollowSymlinks
  AllowOverride All
  Require all granted
  php_value include_path "/srv/[redacted]/phpinclude:/usr/share/pear"
  AddType application/x-httpd-php-source .phps
</Directory>

I never set include path in my php code.

It looks like the value became corrupted and so it went to a default.

Restarted Apache and everything worked.

How would I find out what corrupted that setting? That sounds dangerous.
Never happened in php 7.1.x which I ran from start, or in 7.3.0 which I
also ran from the start. Memory corruption bug?

correction, it reverted to .:/usr/share/pear:/usr/share/php which is
dangerous, php should not have a default that includes the directory the
script is running from even though a lot of people like to do that.

When a path is explicitly set to NOT include the current directory,
including it in a default when the setting becomes corrupt could
(should?) be considered a security flaw.