This appears to be a gap in how the Prism-based backend compiles this pattern.
$ jruby -e 'kwargs = {a: 1}; case kwargs; in {b: 2}; end'
NoMatchingPatternKeyError: {a: 1}: key not found: :b
<main> at -e:1
$ jruby -Xparser.prism -e 'kwargs = {a: 1}; case kwargs; in {b: 2}; end'
NoMatchingPatternError: {a: 1}
<main> at -e:1
This broke the Prism verification build on master when #9542 was merged forward.
This appears to be a gap in how the Prism-based backend compiles this pattern.
This broke the Prism verification build on master when #9542 was merged forward.