test executable always built even when build_by_default is false

[adrianjohnson]

I have an executable used for testing that has build_by_default set to false because the sources for the test executable are three times the size of the rest of the code and most of the time I don't need it built.

If I create a test() that uses the executable it is always built. I would expect it to only get built if I run ninja test.

[nirbheek]

This makes sense, we should not build executables that are explicitly not build-by-default till the test is run.

[pdietl]

Any hope of this getting fixed?

[tp-m]

This makes sense, we should not build executables that are explicitly not build-by-default till the test is run.

I thought it was a conscious design choice in Meson to make sure any test executables get built as part of the build stage and not "on demand" later?

[dcbaker]

There's actually a fixme about doing this in the ninja backend.

[pdietl]

I can give it a go if you'll point me to it

[mthuurne]

The fixme is here; it's in the generic backend code rather than the ninja-specific backend module.

[kayakMike]

The fixme implies that "sometime in the future, these (assuming test executables) are only built right before running tests." That might solve the issue, but the build by default setting for the test executable would be redundant.

Suggestion on this expected functionality might be

• if the test executable is build_by_default == True, build it even when not testing.
• if the test executable is build_by_default == False, build it only before a test.