ANTs: ANTs does not install all files

I am building ANTs with

cmake -C /var/tmp/portage/sci-biology/ants-2.3.1_p20190704/work/ants-2.3.1_p20190704_build/gentoo_common_config.cmake -G Ninja -DCMAKE_INSTALL_PREFIX=/usr -DITK_DIR=/usr/include/ITK-5.0/ -DUSE_SYSTEM_ITK=ON -DUSE_SYSTEM_VTK=ON -DBUILD_TESTING=OFF -DCMAKE_BUILD_TYPE=Gentoo -DCMAKE_TOOLCHAIN_FILE=/var/tmp/portage/sci-biology/ants-2.3.1_p20190704/work/ants-2.3.1_p20190704_build/gentoo_toolchain.cmake  /var/tmp/portage/sci-biology/ants-2.3.1_p20190704/work/ants-2.3.1_p20190704

And I only get the following files installed:

quiethost ~ # equery f ants
 * Searching for ants ...
 * Contents of sci-biology/ants-2.3.1_p20190704:
/etc
/etc/env.d
/etc/env.d/99ants
/usr
/usr/bin
/usr/bin/ANTSAverage2DAffine.sh
/usr/bin/ANTSAverage3DAffine.sh
/usr/bin/ANTSpexec.sh
/usr/bin/ants.sh
/usr/bin/antsASLProcessing.sh
/usr/bin/antsAtroposN4.sh
/usr/bin/antsBrainExtraction.sh
/usr/bin/antsCookTemplatePriors.sh
/usr/bin/antsCorticalThickness.sh
/usr/bin/antsIntermodalityIntrasubject.sh
/usr/bin/antsIntroduction.sh
/usr/bin/antsJointLabelFusion.sh
/usr/bin/antsJointLabelFusion2.sh
/usr/bin/antsLongitudinalCorticalThickness.sh
/usr/bin/antsLongitudinalJointLabelFusion.sh
/usr/bin/antsMultivariateTemplateConstruction.sh
/usr/bin/antsMultivariateTemplateConstruction2.sh
/usr/bin/antsRegistrationSpaceTime.sh
/usr/bin/antsRegistrationSyN.sh
/usr/bin/antsRegistrationSyNQuick.sh
/usr/bin/antsaffine.sh
/usr/bin/antsbashstats.sh
/usr/bin/antsdeformationmag.sh
/usr/bin/antsqsub.sh
/usr/bin/antswithdt.sh
/usr/bin/asymmetry.sh
/usr/bin/basic_ants_example.sh
/usr/bin/buildtemplateparallel.sh
/usr/bin/directlabels.sh
/usr/bin/geodesicinterpolation.sh
/usr/bin/guidedregistration.sh
/usr/bin/landmarkmatch.sh
/usr/bin/lohmann.sh
/usr/bin/multi_template_script.sh
/usr/bin/newAntsExample.sh
/usr/bin/optimalsmooth.sh
/usr/bin/phantomstudy.sh
/usr/bin/shapeupdatetotemplate.sh
/usr/bin/skel.sh
/usr/bin/sliceBySliceOperation.sh
/usr/bin/submitexperimentalbuild.sh
/usr/bin/sygnccavg.sh
/usr/bin/thickstudy.sh
/usr/bin/unbiased_pairwise_registration.sh
/usr/bin/unbiased_pairwise_registration_with_aux_images.sh
/usr/bin/weightedaverage.sh
/usr/lib64
/usr/lib64/ants

Any idea what went wrong? Here is the full build.log. It includes some warnings from my package manager, like:

 * QA Notice: Package triggers severe warnings which indicate that it
 *            may exhibit random runtime failures.
 * /var/tmp/portage/sci-biology/ants-2.3.1_p20190704/work/ants-2.3.1_p20190704/Examples/ImageSetStatistics.cxx:177:5: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]

Though I am unsure whether these are related to my current issue.