Daniel Mendler <mail@daniel-mendler.de> writes:
> If elisp-flymake-byte-compile-executable is nil (the default), the
> absolute file predicate fails and as a result Flymake does not check
> Elisp anymore:
>
> (file-name-absolute-p elisp-flymake-byte-compile-executable)

Apologies, I accidentally posted an old version of the patch which was
then installed.  The attached should fix it.  Please try it (and then
feel free to push it if it works).