Dependency on php5.6-simplexml goes unchecked, is that a bug?

Question

I'm trying to install CiviCRM 4.7.10 on Ubuntu 16.04/WordPress 4.6.1/PHP 5.6.

After completing the installation, when I try to open the CiviCRM node in the WordPress admin menu, I get an error 500 Internal Server error.

The error log in /var/log/apache tells me there is a problem: "Call to undefined function simplexml_load_file".

I fixed this by starting from scratch, this time making sure that I install the php5.6-simplexml package.

Could I have know about this in advance? Should the CiviCRM Installer page (in the WordPress admin) have checked and warn me about this problem?

Answer 1

This is a good question!

Until very recently, this issue hadn't come up, because just about every distro packages the XML extension with PHP. Since you're using Ubuntu 16.04 with PHP 5.6, my guess is you're using the Ondrej PPA. For whatever reason, he packages the XML extension separately. And of course very few people used this PPA with CiviCRM until recently, but now people want Ubuntu LTS with PHP 5.6.

So yes - in theory this check should happen at install. In practice, it doesn't really come up except for folks using the Ondrej PPA (and, I suppose, people who compile their own binaries). So I'd guess this would be considered a "patch welcome" situation - now that PHP7 compatibility has landed in CiviCRM, my guess is that this will bite very few people (who will probably find this page).

If you feel strongly about this and are motivated to submit a patch, feel free to hit me up on chat.civicrm.org (@junglebird) if you need help getting a CiviCRM dev environment together.