Issue #20210 has been updated by mame (Yusuke Endoh). Discussed at the dev meeting. We need a good reason to introduce incompatibility. You say you are fine with the current behavior (exiting immediately), Then, we can't see no reason to change it. This is just my idea: it would be great for prism, as a library, to continue parsing even with an invalid encoding magic comment (maybe as ASCII-8BIT?), but it would be good to keep the behavior of Ruby interpreter as possible. ---------------------------------------- Feature #20210: Invalid source encoding raises ArgumentError, not SyntaxError https://bugs.ruby-lang.org/issues/20210#change-106761 * Author: kddnewton (Kevin Newton) * Status: Open * Priority: Normal ---------------------------------------- I was hoping we could change the error that is raised when an invalid source encoding is found from an ArgumentError to a SyntaxError. First let me say, if this isn't possible for backward compatibility, I understand. Please do not take this as me not caring about backward compatibility. Right now, if you have the script `# encoding: foo\n"bar"`, it will raise an ArgumentError, not a SyntaxError. If there are other syntax errors in the file, there's no way to concat them together to give feedback to the user. If a user wants to consistently handle the errors coming back from a parse, they currently have to rescue ArgumentError and SyntaxError. Ideally it would all be SyntaxError, so we could handle them consistently and append all errors together. -- https://bugs.ruby-lang.org/