[vtk-developers] [ANNOUNCE] New module system landing

[Ben Boeckel]

On Thu, Jan 17, 2019 at 12:27:33 -0500, Sean McBride wrote:
> So I set BUILD_TESTING to off, but that didn't help.

`BUILD_TESTING` is a CTest variable which makes `add_test` a no-op.

> Then I noticed a VTK_BUILD_TESTING, is that new?  Turning it off fixed
> it.  So it's clearly different from BUILD_TESTING.  The setting
> description doesn't help:
> 
> BUILD_TESTING: Build the testing tree
> VTK_BUILD_TESTING: Build all modules by default

Yeah, the description looks like copy-pasta. It has 3 settings:

  ON: if a module is on, build its tests
  WANT: if a module is on, try to turn on test dependencies and build
        tests if those are all available
  OFF: no module tests

How about "Build module testing directories"?

> Is that last description even right?  Why have both these settings
> anyway?  Should setting VTK_FORBID_DOWNLOADS to NO force testing to NO
> also?

I wasn't aware of `VTK_FORBID_DOWNLOADS`. It can be taken into account
before passing it via `ENABLE_TESTS` to `vtk_module_scan`.

--Ben