Dev Install Issue: Cairo must be installed from source to match CI version (1.18)

[jeertmans]

Preliminaries

• I have followed the latest version of the
  installation instructions.
• I have checked the installation FAQ and my problem is either not mentioned there,
  or the solution given there does not help.

Description of error

This is more a documentation issue, but CI is using Cairo 1.18, while Ubuntu users (at least using 22.04) can only install Cairo 1.16 from apt.

Not using Cairo 1.18 will mean that pytest will skip a lot of tests locally, but that may fail in the CI. This is an issue because users will have to trust the CI to pass tests, and possibly wait a long time to check if a patch fixed changes.

TODO

Document this potential issue (only important for dev I guess) and how to build Cairo from source (requires ninja and meson).

System specifications

• OS: Uubuntu 22.04

[behackl]

Adding a remark about this to the developer installation guide is probably a good idea. The restriction was -- unfortunately -- necessary as the new cairo version introduced some minor changes to the graphical output which resulted in failed tests. You can find the corresponding issues / PRs by checking the latest changelog.