[ruby-core:111140] [Ruby master Feature#19117] Include the method owner in backtraces, not just the method name

2 Dec 2022

      Issue #19117 has been updated by mame (Yusuke Endoh).

Discussed at the dev meeting. @matz was basically positive for this proposal. But there is still much to discuss and experiment, so it was decided to discuss for Ruby 3.3.

* How much impact does exception generation have on performance? (Each frame of the backtrace needs to maintain self)
* What notation to use (not discussed at this dev meeting due to priority on Ruby 3.2 issues)

----------------------------------------
Feature #19117: Include the method owner in backtraces, not just the method name
https://bugs.ruby-lang.org/issues/19117#change-100420

* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
----------------------------------------
```
module Foo
  class Bar
    def inspect
      1 + '1'
    end
  end
end

p Foo::Bar.new
```

This code produce the following backtrace:

```
/tmp/foo.rb:4:in `+': String can't be coerced into Integer (TypeError)
	from /tmp/foo.rb:4:in `inspect'
	from /tmp/foo.rb:9:in `p'
	from /tmp/foo.rb:9:in `<main>'
```

This works, but on large codebases and large backtraces the method name isn't always all that revealing, most of the time you need to open many of the locations listed in the backtrace to really understand what is going on.

I propose that we also include the owner name:

```
/tmp/foo.rb:4:in `Integer#+': String can't be coerced into Integer (TypeError)
	from /tmp/foo.rb:4:in `Foo::Bar#inspect'
	from /tmp/foo.rb:9:in `Kernel#p'
	from /tmp/foo.rb:9:in `<main>'
```

I believe that in many case it would allow to much better understand the backtrace without having to jump back and forth between it and the source code.

This is inspired by @ivoanjo 's `backtracie` gem: https://github.com/ivoanjo/backtracie

-- 
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