sinatra-contrib tests fails on truffleruby 24.0.0

[dentarg]

We had passing tests with truffleruby 23.1.2, like ruby 3.2.2, Oracle GraalVM Native [x86_64-linux] on Jan 19.

We now have failing tests with truffleruby 24.0.0, like ruby 3.2.2, Oracle GraalVM Native [x86_64-linux].

Saving the log here

Failures:

  1) Sinatra::Capture hamlit behaves like a template language allows nested captures
     Failure/Error: expect(render(engine, "nested_#{lang}")).to eq("Say Hello World!")

       expected: "Say Hello World!"
            got: "Say Hello \#{::Hamlit::Utils.escape_html((a.strip))}"

       (compared using ==)
     Shared Example Group: "a template language" called from ./spec/capture_spec.rb:41
     # ./spec/capture_spec.rb:36:in `block (3 levels) in <top (required)>'

  2) Sinatra::Capture hamlit behaves like a template language captures content
     Failure/Error: expect(render(engine, "simple_#{lang}")).to eq("Say Hello World!")

       expected: "Say Hello World!"
            got: "Say Hello \#{::Hamlit::Utils.escape_html((a.strip))}!"

       (compared using ==)
     Shared Example Group: "a template language" called from ./spec/capture_spec.rb:41
     # ./spec/capture_spec.rb:32:in `block (3 levels) in <top (required)>'

  3) Sinatra::Capture haml behaves like a template language allows nested captures
     Failure/Error: expect(render(engine, "nested_#{lang}")).to eq("Say Hello World!")

       expected: "Say Hello World!"
            got: "Say Hello \#{(::Haml::Util.escape_html((a.strip))).to_s}"

       (compared using ==)
     Shared Example Group: "a template language" called from ./spec/capture_spec.rb:40
     # ./spec/capture_spec.rb:36:in `block (3 levels) in <top (required)>'

  4) Sinatra::Capture haml behaves like a template language captures content
     Failure/Error: expect(render(engine, "simple_#{lang}")).to eq("Say Hello World!")

       expected: "Say Hello World!"
            got: "Say Hello \#{(::Haml::Util.escape_html((a.strip))).to_s}!"

       (compared using ==)
     Shared Example Group: "a template language" called from ./spec/capture_spec.rb:40
     # ./spec/capture_spec.rb:32:in `block (3 levels) in <top (required)>'

cc @eregon

[eregon]

@andrykonchin Could you investigate?
From the output it looks like #{} interpolation is not done, but that surely works fine in regular Ruby code.
Maybe some Regexp issue or so since this is likely interpolation in some template or so?