Marshal.dump with frozen string literals differs on --debug flag

[segiddins]

Environment Information

jruby 9.4.3.0 (3.1.4) 2023-06-07 3086960792 OpenJDK 64-Bit Server VM 19.0.1+10-21 on 19.0.1+10-21 +jit [arm64-darwin]

Expected Behavior

❯ chruby-exec jruby-9.4 -- ruby -vwe "$(printf "# frozen_string_literal: true\np Marshal.dump('')")"
jruby 9.4.3.0 (3.1.4) 2023-06-07 3086960792 OpenJDK 64-Bit Server VM 19.0.1+10-21 on 19.0.1+10-21 +jit [arm64-darwin]
"\x04\bI\"\x00\x06:\x06ET"

Actual Behavior

❯ chruby-exec jruby-9.4 -- ruby --debug -vwe "$(printf "# frozen_string_literal: true\np Marshal.dump('')")"
jruby 9.4.3.0 (3.1.4) 2023-06-07 3086960792 OpenJDK 64-Bit Server VM 19.0.1+10-21 on 19.0.1+10-21 +jit [arm64-darwin]
"\x04\bI\"\x00\a:\x06ET:\x18@debug_created_info[\aI\"\a-e\x06;\x00Ti\a"

I would expect --debug not to cause the @debug_created_info ivar to be dumped.

[ahorek]

@debug_created_info is an internal variable for tracking frozen string literals, see https://bugs.ruby-lang.org/issues/11725 and bfd0b76

MRI just hides it from Marshal.dump since ruby/ruby@6964c06 which isn't really a good approach in the first place, but it shouldn't be hard to replicate it...

[enebo]

heh. I don't remember imlpementing this at all. So I guess the FIXME I added was relevant after all.