Be louder when graphics is missing for geospatial

[mjcarroll]

🦟 Bug fix

Summary

Users building from source could get in a situation where dependencies of the graphics component weren't available, so that the component is not created. In this case, the geospatial component still has a hard dependency on the graphics component, but it is still attempting to build.

This adds gating logic to prevent the geospatial component from building when the graphics component isn't build and adds a warning message for the user.

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (bc24ece) 83.65% compared to head (660fda4) 83.65%.

Additional details and impacted files

@@             Coverage Diff             @@
##           gz-common5     #573   +/-   ##
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  Coverage       83.65%   83.65%           
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  Files              92       92           
  Lines           10285    10285           
===========================================
  Hits             8604     8604           
  Misses           1681     1681           

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[Ryanf55]

The warning is much more obvious and it skips building geospatial if graphics do not exist. Thanks!

I'll create another bug for the follow up (assuming it's optional) since it's a different problem.

[scpeters]

I thought the DEPENDS_ON_COMPONENTS parameter would generate a complaint if the needed component wasn't available, but apparently it doesn't

[mjcarroll]

That was also my understanding, but does not seem to be the case.

[scpeters]

an alternative would be to change every find_package call with REQUIRED_BY graphics to REQUIRED_BY graphics geospatial; not sure that it makes more sense though

EDIT: it's what we do in gz-physics

[mjcarroll]

an alternative would be to change every find_package call with REQUIRED_BY graphics to REQUIRED_BY graphics geospatial; not sure that it makes more sense though

It would be the other way around, correct? Anyone who requires geospatial also will require graphics.

[mjcarroll]

This is failing, on focal because the folders are being processed geospatial then graphics