(master) frozen string errors with --debug #7924
Description
Environment Information
Using jruby HEAD:
$ bin/jruby -v
jruby 9.4.4.0-SNAPSHOT (3.1.4) 2023-06-18 656f9d6570 OpenJDK 64-Bit Server VM 11.0.20.1+1-post-Ubuntu-0ubuntu122.04 on 11.0.20.1+1-post-Ubuntu-0ubuntu122.04 [x86_64-linux]
$ uname -a
Linux juno 6.2.0-1011-lowlatency #11~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Aug 16 16:22:57 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
Reproduction
File foo.rb:
# frozen_string_literal: true
puts RUBY_DESCRIPTION
s = +"hello"
puts s.frozen?
s.force_encoding(::Encoding::ASCII_8BIT)When run with bin/jruby foo.rb:
jruby 9.4.4.0-SNAPSHOT (3.1.4) 2023-06-18 656f9d6570 OpenJDK 64-Bit Server VM 11.0.20.1+1-post-Ubuntu-0ubuntu122.04 on 11.0.20.1+1-post-Ubuntu-0ubuntu122.04 [x86_64-linux]
false
When run with bin/jruby --debug foo.rb
jruby 9.4.4.0-SNAPSHOT (3.1.4) 2023-06-18 656f9d6570 OpenJDK 64-Bit Server VM 11.0.20.1+1-post-Ubuntu-0ubuntu122.04 on 11.0.20.1+1-post-Ubuntu-0ubuntu122.04 [x86_64-linux]
false
FrozenError: can't modify frozen String, created at foo.rb:5
force_encoding at org/jruby/RubyString.java:6663
force_encoding at org/jruby/RubyString.java:6659
<main> at foo.rb:7
This error does not occur with jruby-9.4.2.0.
This was discovered by upstream nokogiri integration testing: https://github.com/sparklemotion/nokogiri/actions/runs/6076083505/job/16483500598