Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> Why is the byte-compiler silent about the "missing" `case' and `loop'?
>
> AFAIK it does report them as missing, at the end of the compilation
> (it can't report them right away because `loop' and `case' might be
> defined as functions further down in the file).

Try the attached test.el (with emacs -Q).

1. The compiler doesn't get to "the end of data" ritual.

2. How would I interpret the error?

   1:40 ends points to param line but the actual error report - the
   `marker' variable - is elsewhere.