This is on AL9, which I believe has CWP PHP 7.4.
But the paths show 7.1.
Only location that had the intl.so in was:
/usr/local/cwp/php71/lib/php/extensions/no-debug-non-zts-20170718/intl.so
Copied it over to:
/usr/local/cwp/php71/lib/php/extensions/no-debug-non-zts-20190902
Both:
/usr/local/src/intl-3.0.0/.libs/
/usr/local/src/intl-3.0.0/modules/
where empty.
Trying to rebuild PHP now.
Only server to be having this problem.
And it only showed when updating RoundCube to 1.5.11.
You run a PHP module check with php -m, and it lists intl.
php -v doesn't show any errors either.