Collate multiple executables with dependencies

[markfinal]

Written in the form of test executables.

Suppose a package has multiple tests T_, exercising multiple modules M_ within that package.
Suppose also that each of those modules have dependencies D, from another package.

I do not want to prescribe how users should write tests.

The problem comes down to which build mode is used.

In Native builds, each test can be published into a new directory, or the same.

In IDE project builds, the dependencies must always be besides the built executable.

So if the build scripts are written so that dependencies and tests are collated into the same directory, this doesn't work for IDE builds.