Yesterday I shared a half backed idea about having hosts help more with automated testing for WordPress. Continuing that thread, there are a handful of things that need to be figured out. The first of which is what are the pieces of the WordPress Stack that we need to track and are the real variables. Here is my initial list (along with tickets for many showing when WordPress has been bitten).
- PHP Version (all the way down)
- MySQL Version (or MySQL variant)
- OpenSSL Version. ( #30434 showed that different versions of OpenSSL respond differently to the order that SSL Certificates are presented)
- ImageMagick version. #36501 demonstrates that we can have issues that only show up in certain versions of ImageMagick.
- Curl version.  demonstrates this necessity.
- PHP Extensions installed. #36629
What else? I’m sure there are things that I’m missing. What variable in the WordPress hosting stack have you noticed cause a bug?