fix #1750: check problematic owner first to avoid cyclic reference

[liufengyun]

Fix #1750: check problematic owner first to avoid cyclic reference.

I'm not sure if this is the right fix, could you please advise @odersky ?

[liufengyun]

/rebuild

[odersky]

I don't think /rebuild works. You have to restart from the web interface, clicking on Details first.

[odersky]

@felixmulder I tried restarting from the web interface but that did not do anything either. I think it would be good to resurrect /rebuild. Sometimes it is really essential.

[felixmulder]

We have an alternative way to restart tasks currently.

$ drone build start lampepfl/dotty <buildNbr>

The build number can be found in two ways, either by:

$ drone build list lampepfl/dotty

or by clicking through the web interface. I restarted this job by running the first command for build number 392.

I'll look into the possibility of resurrecting /rebuild

[felixmulder]

@liufengyun:

!!  86 - neg/i1750.scala                           [expected compilation failure]

[liufengyun]

Thanks @felixmulder . I was wondering why it failed on drone, while pass locally -- the fix is exactly for #1750.

[smarter]

I would advise against moving ExtractAPI without thinking deeply about the consequences. For example ElimRepeated is going to replace T* by Seq[T], which means that if the user replaces def foo(x: Foo*) by def foo(x: Seq[Foo]) in some source file, this will not be considered to be an API change, but this is wrong since it will break everything that tries to call foo assuming it takes a Foo*.

[liufengyun]

@smarter the comment makes sense, a true concern. Let's try the other way around.

[felixmulder]

Add a comment here for why it was moved up?

[liufengyun]

@felixmulder Thanks for looking at it. I tend to agree moving RefChecks before Pickler is a huge change we should try our best to avoid. Let's wait for some better fix that deprecate this one.

[odersky]

@liufengyun What was the reason of moving RefChecks before ExtractDependencies? Did you see a crash in ExtractDependencies?

[liufengyun]

@odersky : exactly as you noticed, there is CyclicReference exception in ExtractApi.

[liufengyun]

superseded by #1913 , close this now.