fix: ACTS_BUILD_EXAMPLES requires ACTS_BUILD_PLUGIN_ROOT

[AJPfleger]

Examples needs the Root Plugin to build.

with

cmake -S acts -B build \
  -DACTS_BUILD_EXAMPLES=ON

I get the error

CMake Error at Examples/Detectors/TGeoDetector/CMakeLists.txt:14 (target_link_libraries):
  Target "ActsExamplesDetectorTGeo" links to:

    Acts::PluginRoot

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.



CMake Error at Examples/Io/Root/CMakeLists.txt:37 (target_link_libraries):
  Target "ActsExamplesIoRoot" links to:

    Acts::PluginRoot

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.

[github-actions]

📊: Physics performance monitoring for a8f1d8e

Full contents

physmon summary

• ✅ Particles fatras
• ✅ Particles geant4
• ✅ Particles ttbar
• ✅ Vertices ttbar
• ✅ Truth tracking (KF)
• ✅ Truth tracking (GSF)
• ✅ Truth tracking (GX2F)
• ✅ Truth tracking (KF refit)
• ✅ Truth tracking (GSF refit)
• ✅ CKF finding performance | trackfinding | single muon | truth smeared seeding
• ✅ CKF fitting performance | trackfinding | single muon | truth smeared seeding
• ✅ CKF track summary | trackfinding | single muon | truth smeared seeding
• ✅ Seeding trackfinding | single muon | truth estimated seeding
• ✅ CKF finding performance | trackfinding | single muon | truth estimated seeding
• ✅ CKF fitting performance | trackfinding | single muon | truth estimated seeding
• ✅ CKF track summary | trackfinding | single muon | truth estimated seeding
• ✅ Seeding trackfinding | single muon | default seeding
• ✅ CKF finding performance | trackfinding | single muon | default seeding
• ✅ CKF fitting performance | trackfinding | single muon | default seeding
• ✅ CKF track summary | trackfinding | single muon | default seeding
• ✅ Seeding trackfinding | single muon | orthogonal seeding
• ✅ CKF finding performance | trackfinding | single muon | orthogonal seeding
• ✅ CKF fitting performance | trackfinding | single muon | orthogonal seeding
• ✅ CKF track summary | trackfinding | single muon | orthogonal seeding
• ✅ Seeding trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF finding performance | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF fitting performance | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF track summary | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Ambisolver finding performance | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ IVF notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF gauss notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF grid time | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Seeding trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF finding performance | trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF fitting performance | trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF track summary | trackfinding | ttbar with 200 pileup | default seeding
• ✅ Ambisolver finding performance | trackfinding | ttbar with 200 pileup | default seeding
• ✅ ML Ambisolver | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF gauss notime | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF grid time | trackfinding | ttbar with 200 pileup | default seeding
• 🔵️ Comparison - Truth tracking (GX2F vs KF)

[paulgessinger]

@benjaminhuth

[benjaminhuth]

Thanks for pointing that out... I just changed that in #5032 so that examples depends not necessarily on ROOT.
The reason the build fails is that ACTS_BUILD_EXAMPLES_ROOT defaults to ON, which I overlooked in #5032.

So there are several options:

• Set ACTS_BUILD_EXAMPLES_ROOT=OFF by default
• Set set_option_if(ACTS_BUILD_PLUGIN_ROOT ACTS_BUILD_EXAMPLES_ROOT)
• Remove the ACTS_BUILD_EXAMPLES_ROOT and only have ACTS_BUILD_PLUGIN_ROOT, so that we get the behaviour with ACTS_BUILD_EXAMPLES AND ACTS_BUILD_PLUGIN_ROOT (actually I'm slightly leaning towards that, although there is ROOT functionality in Examples unrelated to the plugin.

Any opinions @andiwand @paulgessinger @AJPfleger?

[AJPfleger]

I feel the 2nd option feels most natural to me.
1st is not really what I would expect, when building all examples.
But no strong preference between 2nd and 3rd.

[benjaminhuth]

Okay, let's go with option 2 for now since it is also the least intrusive change

[benjaminhuth]

Looks good to me!

[paulgessinger]

Docs failure seems to be real, @AJPfleger can you look into it?

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud