Dubious value auto-detected for hslogger's buildtests flag

[peti]

I'm not sure what to make of the following behavior in Cabal 1.24. hslogger has a flag buildtests that marks the test suite "buildable" when enabled, but it defaults to "disabled". Now, the effective value of the flag is determined automatically by Cabal, but it sticks to the "disabled" setting, apparently not realizing that it could build the test suite if "enabled" would be chosen. As a result, users cannot run the test suite unless they realize that flag exists and specify it explicitly:

$ cabal get hslogger
Downloading hslogger-1.2.10...
Unpacking to hslogger-1.2.10/
$ cd hslogger-1.2.10/
$ cabal configure -v --enable-tests 
[...]
Configuring hslogger-1.2.10...
Flags chosen: buildtests=False, small_base=True
[...]
$ cabal test 
Package has no buildable test suites.

Now I wonder: are we happy with that result? Or can a legitimate case be made that Cabal should strive to maximize the set of buildable components in a package?

[23Skidoo]

/cc @grayjay, @kosmikus

[kosmikus]

I'm not sure if we can really do anything better here. In many (other) cases, it is explicitly the desire to respect the default flag setting as much as possible. I'm somewhat surprised what the purpose of this particular flag is. Sounds as if one would get exactly the desired behaviour if the flag was just removed.

[peti]

That is what I thought, too, that flag seems like a complete re-implementation of --enable-tests and it should probably be removed. I realize that there is no obvious one true correct solution for what the solver should do in this particular case and leaving everything as-is is probably not a bad choice. Still, it feels a little odd that --enable-tests is given, there are test suites which could be built if the appropriate automatic flag were enabled, but Cabal just won't do it. Not sure what to do about it either.

[grayjay]

I looked at hslogger's history, and it seems like the buildtests flag was added before cabal supported test suites, when the component was an executable.

[grayjay]

I think that the solver should continue to prefer flags' default values. We could add a flag to cabal to change that preference or force components to be buildable, if that would be a useful feature. I'm closing this issue, though, since it seems like the best solution is to remove the buildtests flag from hslogger.