TribitsHelloWorld does ctest but testing is not enabled

[kotcherd]

[bartlettroscoe]

You need to turn on the tests, like for any TriBITS-based project:

• https://tribitspub.github.io/TriBITS/build_ref/index.html#enable-or-disable-tests-for-specific-packages

See:

https://github.com/TriBITSPub/TriBITS/blob/8c1874ca69280c9c9e8346fc96b2f068971e54d4/test/core/ExamplesUnitTests/TribitsHelloWorld_Tests.cmake#L16

TriBITS projects, by default, assume the user is just trying to build and install them, without enabling or running tests.