Feature #22136
Updated by byroot (Jean Boussier) 3 months ago
### Expected behavior
If I'm tracking down a problem and suspect an error might be swallowed somewhere, I do run my test case with `RUBYOPT="-d"` (or simply set `$DEBUG = true`.
I do expect the program to execute all in the same way than without `-d`, expect for extra output on STDERR.
### Actual behavior
If some code happens to call `sprintf` or `String#%` with too many arguments, then it will raise an error and likely break the program, preventing me from simply running the same code but in debug mode.
### Reproduction
```
$ ruby -e 'sprintf("foo", "bar"); p :ok'
:ok
$ ruby -We 'sprintf("foo", "bar"); p :ok'
-e:1: warning: too many arguments for format string
:ok
$ ruby -dWe 'sprintf("foo", "bar"); p :ok'
Exception 'LoadError' at .../lib/ruby/4.0.0/rubygems.rb:1423 - cannot load such file -- rubygems/defaults/operating_system
Exception 'LoadError' at .../lib/ruby/4.0.0/rubygems.rb:1438 - cannot load such file -- rubygems/defaults/ruby
Exception 'ArgumentError' at -e:1 - too many arguments for format string
Exception 'RuntimeError' at <internal:ast>:96 - cannot get AST for ISEQ compiled by prism
-e:1:in 'Kernel#sprintf': too many arguments for format string (ArgumentError)
from -e:1:in '<main>'
```
### Bug or Feature?
I looked around the Ruby codebase, as far as I can tell this is the only method behaving this way (aside from its aliases like `String#%`).
So I filed this as a Feature, but really in my opinion it is a bug.
Pull Request: https://github.com/ruby/ruby/pull/17579