Potential removal of the gtest package

[cgcgcg]

We are considering to remove the gtest package (https://github.com/trilinos/Trilinos/tree/master/commonTools/gtest) from Trilinos as part of the upcoming 17.0 release.

Options to replace the package dependency could be either the gtest TPL or a private snapshot of gtest.

Please let us know if you anticipate that this removal could cause any issues.

See also:

• GTest as a TPL #8001.
• https://google.github.io/googletest/quickstart-cmake.html

[alanw0]

I think it will be a minor pain but we'll manage, and it will be an improvement.
spack builds can easily grab gtest externally, and "raw" cmake builds will simply require the user to point to a user-supplied gtest installation. Right?
I think this makes sense, Trilinos shouldn't need to carry an internal copy of a TPL.

[cgcgcg]

Yes, that seems like the most reasonable approach. We already have a gtest TPL https://github.com/trilinos/Trilinos/blob/master/cmake/TPLs/FindTPLgtest.cmake. Maybe we can even augment that to pull in a fresh gtest via FetchContent.

[cgcgcg]

@trilinos/stk @trilinos/krino @trilinos/compadre @trilinos/rol

[ccober6]

@trilinos/percept @trilinos/seacas

[kuberry]

compadre uses gtest for some of its unit testing. We could add a flag based on TPL gtest being available and otherwise disable that portion of tests.

[cgcgcg]

Making the TPL gtest a required dependency for tests should be enough, no? I guess we do want to avoid that we accidentally disable the tests in builds where they were running before.

[sebrowne]

GTest has been removed as a package with #14719