Issue #20968 has been updated by mame (Yusuke Endoh). This issue was discussed briefly at the dev meeting and Matz agreed with koic's expectation. https://github.com/ruby/dev-meeting-log/blob/47882270bd90fb0027e8fe62e421b39... --- The following is my opinion. I agree that this is not a bug, but I think koic's expectations are clearly better than the current from a user benefit perspective, not from a consistency perspective. I think it is significantly unlikely that `<internal:array>:211` is valuable information for user to debug a bug. It would be more convenient to combine `<internal>` backtraces into one and substitute the name of the calling Ruby source file and line number, as in the current C-implemented method. ---------------------------------------- Bug #20968: `Array#fetch_values` unexpected method name in stack trace https://bugs.ruby-lang.org/issues/20968#change-112027 * Author: koic (Koichi ITO) * Status: Open * ruby -v: ruby 3.4.0dev (2024-12-19T04:44:56Z master 2783868de2) +PRISM [x86_64-darwin23] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- It seems that the current Ruby implementation is displaying unexpected method name in stack trace. ## Expected Similar to `Hash#fetch_values`, the method name `Array#fetch_values` is expected to be displayed in the stack trace. ```console $ ruby -e '{k: 42}.fetch_values(:unknown)' -e:1:in 'Hash#fetch_values': key not found: :unknown (KeyError) from -e:1:in '<main>' $ ruby -e '[1].fetch_values(42)' -e:1:in 'Array#fetch_values': index 42 outside of array bounds: -1...1 (IndexError) from -e:1:in '<main>' ``` ## Actual The stack trace displays the `Array#fetch` method, which user is not aware of, along with the `<internal.array>` stack trace. ```console $ ruby -e '[1].fetch_values(42)' <internal:array>:211:in 'Array#fetch': index 42 outside of array bounds: -1...1 (IndexError) from <internal:array>:211:in 'block in Array#fetch_values' from <internal:array>:211:in 'Array#map!' from <internal:array>:211:in 'Array#fetch_values' from -e:1:in '<main>' ``` It likely requires an approach such as implementing it in C, as suggested in https://github.com/ruby/ruby/pull/11555. -- https://bugs.ruby-lang.org/