$releasever and $arch substitution in url and mirrorlist, and "Closest mirror" kickstart support?

[Adam Williamson]

So like Vadym Chepkov way back in 2010, I find myself wanting to write
very generic kickstart files, for validation testing. The Kickstart docs
claim:

https://fedoraproject.org/wiki/Anaconda/Kickstart#url

"     --mirrorlist= 

        The mirror URL to install from. Variable substitution is done
for $releasever and $basearch in the url (added in F19)."

but I tried using this, and it doesn't seem to work. A kickstart with
this line:

url --mirrorlist=https://mirrors.fedoraproject.org/mirrorlist?repo=fedora-$releasever&arch=$arch

or this one:

url --url=https://dl.fedoraproject.org/pub/fedora/linux/releases/$releasever/Fedora/$arch/os/

just gives me an error on the Installation Source spoke. When I enter
the spoke, $releasever and $arch are included verbatim in the URL. If I
manually substitute them with correct values then go back to hub, it
works (indicating I'm using the right URL, but the substitution just
isn't happening). I've tested with 19 and 20; it doesn't work with
either.

Am I doing something wrong, or did this never actually work in a
release? Can it be fixed?

Also, shouldn't there be a way to duplicate the interactive network
install's default "Closest mirror" behaviour in a kickstart without
having to pass any URL explicitly at all? I'd expect that simply "url
--mirrorlist" would do this, but in fact it just dies, stating that a
URL is required...I don't see that this limitation makes sense, a
kickstart-driven install should be able to 'just use defaults' like an
interactive one can here.

Thanks!

(yeah, this is the usual adamw, I subscribed to this list ages ago, with
an old personal address...)
-- 
adamw