Report include/inheritance location for missing abstract method implementation

[bararchy]

So, this seems to be the most cryptic error message up to date, can we get some info added on where the actual issue is?

Parse:                             00:00:00.000269260 (   0.50MB)
Semantic (top level):              00:00:00.293037005 (  91.04MB)
Semantic (new):                    00:00:00.002857463 (  91.04MB)
Semantic (type declarations):      00:00:00.033981050 (  91.04MB)
In /usr/share/crystal/src/enumerable.cr:37:16

 37 | abstract def each(&block : T -> _)
                   ^---
Error: abstract `def Enumerable(T)#each(&block)` must be implemented by SerialObject

This error is with --error-trace enabled

[ysbaddaden]

As the error message says: you must implement SerialObject#each(&block) to satisfy the Enumerable#each(&block) abstract method.

Abstract methods on generics weren't properly checked before 0.30.

[asterite]

Maybe we can somehow also point to where the class is defined. It's tough because so far errors only have one location.

[asterite]

I also wonder whether that should have been a warning instead of an error, at least for 0.30.0. I can't remember if this was checked for generics before...

[RX14]

The error message is hardly cryptic, but the location of the error should be the location of include Enumerable(T) in the class.

[asterite]

Oh, that's a good idea... but it's also hard to. implement because we don't keep track of where is the include of a class.

[RX14]

It might be hard to implement, but I think it is worth implementing...

Also, the abstract `def Enumerable(T)#each(&block)` looks weird, the def should probably go.

This is a fairly minor visual issue, so it doesn't have to be implemented right now.

[bararchy]

So, my main issue was that as we have quite a big project with multiple devs I thought that SerialObject is something from Crystal, I would have figured it out sooner if for example it would at least point out that SerialObject was in this and that file in this and that line (just the class\module etc..)