fix OSX build failing on warning

[konserw]

Summary

fix OSX build by removing -werror

Details

Motivation and Context

OSX builds started failing becouse of harmless warning treated as error

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist:

• It is my own work, its copyright is implicitly assigned to the project and no substantial part of it has been copied from other sources (including Stack Overflow). In rare occasions this is acceptable, like in CMake modules where the original copyright information should be kept.
• I'm using the same code standards as the existing code (indentation, spacing, variable naming, ...).
• I've added tests for my code.
• I have verified whether my change requires changes to the documentation
• My change either requires no documentation change or I've updated the documentation accordingly.
• My branch has been rebased to master, keeping only relevant commits.

[coveralls]

Coverage remained the same at 63.329% when pulling 879a13a on konserw:osxfix into 70fa12c on cucumber:master.

[matlo607]

What are those harmless warnings ?

[konserw]

https://travis-ci.org/cucumber/cucumber-cpp/jobs/341094255 ->

In file included from ../examples/CalcQt/features/step_definitions/BoostCalculatorQtSteps.cpp:4:
../examples/CalcQt/features/step_definitions/CalculatorQtSteps.cpp:40:5: error: ignoring return value of function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
    QTest::qWaitForWindowExposed(&ctx->calculator);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

I just tried assigning to a variable which resulted in:
https://travis-ci.org/konserw/cucumber-cpp/jobs/341560068

../examples/CalcQt/features/step_definitions/CalculatorQtSteps.cpp:39:10: error: variable ‘_’ set but not used [-Werror=unused-but-set-variable]
     bool _; //just to suppress warning
          ^
cc1plus: all warnings being treated as errors

Honestly I don't think we should add artificial code just to suppress warnings. They are warnings and not errors after all.

[konserw]

I'll try with #pragma clang diagnostic ignored "-Wunused-result"

[matlo607]

I proposed 1b5ed23 in my pull requests (#180, #181, #182, #183).
The result of QTest::qWaitForWindowShown / QTest::qWaitForWindowExposed should be actually used.

[matlo607]

By the way, do you know who is in charge of reviewing pull requests on this project ?
A lot of pull requests are green and have not been accepted nor rejected.

[konserw]

but your use of it doesn't make any sense - that waiting function is there for user to actually see what is happening (how cucumber is "clicking") if user wants to; and by default does nothing (waits for 0 ms)

As for reviewers: @paoloambrosio @muggenhor and I supose me...

[matlo607]

I trust you if you say so. Actually I am not a cucumber user, I just had to build it and provide an artifact for a team and fixed the build with boost-1.66.0
I will remove commit 1b5ed23 from my pull request once you will have fixed this issue.
Thanks for your feedback.

[konserw]

Ok so the question now is if we need to keep -werror and apply this PR or could we just disable -werror ?
@muggenhor @paoloambrosio what do you think ?

[konserw]

I went with disabling -werror on my devel branch. If merging is unblocked I would push it also here.

[matlo607]

Any news about the reviewers ?
This pull request has been opened for more than 1 month ago.

[konserw]

@matlo607 could you please create pull request with just removing -werror ? I'll then review and merge it . Afterwords I'll review rest of your PRs (I've already tested them ;) )

[konserw]

Merged as part of #189