Commands you use every day in the CLI? In your editor?

I can trivially enter Emacs and modify Apache config when it breaks backwards compat between distribution upgrades, but when it's infrastructure as code...

I can’t think of a single time I’ve had an Apache config break with upgrades - other than having to recompile the webservice proxy module to change the case of the Upgrade header for a device that doesn’t work with the standards and is case sensitive

(Major upgrades every couple of years break the binary compatibility)

I am pretty confident it broke for me between 12.04 and 14.04 Ubuntu releases, and I am pretty sure both were already in the 2.x series.

Most likely the change in NameVirtualHost behaviour as listed at https://httpd.apache.org/docs/2.4/upgrading.html, but there are a bunch of other changes too.

Oh sure every few years when you upgrade to a new OS, but not a normal security upgrade.