only fetch acts and compile it if not found in image

[tomeichlersmith]

I am updating ldmx-sw, here are the details.

What are the issues that this addresses?

This does not have a corresponding issue here. I am following up with LDMX-Software/dev-build-context#115 while preparing for a v5 release of the ldmx/dev image.

Check List

• I successfully compiled ldmx-sw with my developments. I test compiled with the newer image that has Acts locally. The CI will check that these developments work with the v4.2.2 image that does not have Acts.
• I read, understood and follow the coding rules.
• I ran my developments and the following shows that they are successful.

[tvami]

Isn't the solution to move those virtual destructors to be non virtual (even tho they are supposed to be virtual but given that ACTS didnt do them virtual...)?

[tomeichlersmith]

That would be the solution, but that would involve editing Acts and I do not want to do that. There are also other warnings (turned errors) from Acts that are seen by the compiler that we are ignoring with the same SYSTEM strategy. I'm just localizing the SYSTEM include to be more specific.

ldmx-sw/CMakeLists.txt

Line 39 in 79fcb61

include_directories(SYSTEM Tracking/acts/Core/include)

[tvami]

Yeah I agree that editing ACTS is beyond what we should do, but the earlier warning I saw in your original commit were about the inherited class which we have control over. It's true that I didnt look at the full list, so maybe there is some stuff that we have no control over... in that case going back to the SYSTEM approach is fine