PHP Fatal error: Uncaught Error: Class 'Imagick' not found

[Dustin Kirkland ]

There seems to have been a regression in php7 and/or php-imagick since 16.04.

Using the pictor package from Ubuntu Universe, I have failures in /var/log/apache2/error.log:

[Mon Feb 05 12:51:08.495059 2018] [:error] [pid 25617] [client ::1:47710] PHP Fatal error: Uncaught Error: Class 'Imagick' not found in /usr/share/pictor/index.php:237\nStack trace:\n#0
...

There seems to be a weird combination of PHP 7.0 and 7.1 packages on my system. Perhaps that's the root of the problem?

kirkland@x250:/srv/media/src/pictor/pictor$ dpkg -l | grep php
ii libapache2-mod-php7.0 7.0.22-0ubuntu0.16.04.1 amd64 server-side, HTML-embedded scripting language (Apache 2 module)
ii php-common 1:54ubuntu1 all Common files for PHP packages
ii php-getid3 1.9.14+dfsg-1 all scripts to extract information from multimedia files
ii php-imagick 3.4.3~rc2-2ubuntu3 amd64 Provides a wrapper to the ImageMagick library
ii php7.0-cli 7.0.22-0ubuntu0.16.04.1 amd64 command-line interpreter for the PHP scripting language
ii php7.0-common 7.0.22-0ubuntu0.16.04.1 amd64 documentation, examples and common module for PHP
ii php7.0-json 7.0.22-0ubuntu0.16.04.1 amd64 JSON module for PHP
ii php7.0-opcache 7.0.22-0ubuntu0.16.04.1 amd64 Zend OpCache module for PHP
ii php7.0-readline 7.0.22-0ubuntu0.16.04.1 amd64 readline module for PHP
ii php7.1-cli 7.1.11-0ubuntu0.17.10.1 amd64 command-line interpreter for the PHP scripting language
ii php7.1-common 7.1.11-0ubuntu0.17.10.1 amd64 documentation, examples and common module for PHP
ii php7.1-json 7.1.11-0ubuntu0.17.10.1 amd64 JSON module for PHP
ii php7.1-opcache 7.1.11-0ubuntu0.17.10.1 amd64 Zend OpCache module for PHP
ii php7.1-phpdbg 7.1.11-0ubuntu0.17.10.1 amd64 server-side, HTML-embedded scripting language (PHPDBG binary)
ii php7.1-readline 7.1.11-0ubuntu0.17.10.1 amd64 readline module for PHP