Philipp <p.stephani2@gmail.com> schrieb am Fr., 6. Apr. 2018 um 03:25 Uhr:

>
> Loading the following file triggers an assertion failure:
>
> ;;; -*- lexical-binding: t; -*-
> (defvar 1)
>
> $ emacs -Q -batch -l /tmp/crash.el
> eval.c:772: Emacs fatal error: assertion failed: SYMBOLP (sym)
> Fatal error 6: Abort trapAbort trap: 6
>
> This is because Fdefvar lacks a CHECK_SYMBOL in the second branch
> (lexical binding but only one argument)
>

Here is a patch.