Back in 2010 I wanted to try out Scala. I fired up the REPL and did this:

    scala> 1+2
    res0: Int = 12

Here is a blog post I wrote about it at the time: https://illuminatedcomputing.com/posts/2010/11/no-luck-tryin...

I was running under Cygwin and the issue was something about the Java-based readline library.

I filed a ticket (linked in my blog post but the link is broken now), but the maintainers' response was something like "Yeah right. Closed."

You'd think compiler bugs would be more obscure than 1+2. :-)