Question: make subunit dependency explicit

[dernasherbrezon]

Currently subunit dependency checked during the configuration step. If subunit exists, then libcheck will have a dependency on it. If not, then there will be no dependency.

However this might bring some instability to the build (builds will be not reproducable). Consider the scenario:

• configure and build check
• subunit dependency is missing. libcheck builds fine, but without subunit
• install subunit
• build any third party code with subunit dependency and libcheck. It should fail.

Another downside of the current approach: subunit is linked even if it was not used (transitive dependency).

I was wondering if the following scenario makes sense:

• Setup optional cmake parameter: "ENABLE_SUBUNIT"
• If parameter is defined, then search for subunit (somewhere here https://github.com/libcheck/check/blob/master/CMakeLists.txt#L396 )
• If subunit cannot be found, then fail the build
• If subunit found, then continue with subunit dependency
• By default ENABLE_SUBUNIT=0 (libcheck can work pretty well without subunit).

[mikkoi]

I agree. This needs to be added to CMake build.