Ruby Issue Tracking System

07/02/2026

01:01 AM Ruby Bug #22140 (Open): Prism rejects a trailing comma in a pattern-matching loop condition before do, while parse.y accepts it

Prism rejects the following code, while parse.y accepts it:
Prism:
```sh
$ ruby --parser=prism -ce 'while a in b, do end'
ruby: -e:1: syntax error found (SyntaxError)
> 1 | while a in b, do end
| ^~ expected a... Kai (kai matsudate)

06/08/2026

04:13 PM Ruby Bug #22095 (Closed): Prism rejects a multiple assignment in a rescue modifier value that parse.y accepts

## Problem
parse.y and Prism parse the following differently:
```ruby
a rescue b, c = 1
```
parse.y accepts it, but Prism rejects it.
## Cause
In the grammar, the value of a rescue modifier is a statement, so it may itse... Kai (kai matsudate)

06/01/2026

04:47 PM Ruby Bug #22089: Prism accepts statement modifiers in if/unless/elsif conditions that parse.y rejects

I'm the reporter. It shows as anonymous due to recreating my account, but I'm following this. Kai (kai matsudate)