Quoting my own email I think this is the relevant bit. I don't think it's an issue in haunt, but something with qt:

srfi/srfi-1.scm:241:2: In procedure map:
In procedure map: Wrong type argument: "https://www.qt.io/"
building pages in '/tmp/gnu.org/software/guix'...

Le 5 septembre 2022 14:04:10 GMT+02:00, zimoun <zimon.toutoune@gmail.com> a écrit :
>Hi,
>
>On lun., 05 sept. 2022 at 12:59, "pelzflorian (Florian Pelz)" <pelzflorian@pelzflorian.de> wrote:
>> zimoun <zimon.toutoune@gmail.com> writes:
>>> $ LANG=en_US.UTF-8 GUIX_WEB_SITE_LOCAL=yes guix environment -C -m manifest.scm \
>>>                           -E LANG -E GUIX_WEB_SITE_LOCAL  --share=/tmp         \
>>>                           -- haunt build
>>
>> Yes but `guix build -f .guix.scm` fails for me too, perhaps because it
>> uses latest-guix from %default-channels.  It’s not fixed by using old
>> haunt, so I guess a change in guix makes the difference, but I have not
>> found the commit and will not continue looking for it immediately.
>
>The file manifest.scm contains:
>
>--8<---------------cut here---------------start------------->8---
>(define the-good-guile
>  (car (assoc-ref (package-native-inputs guix) "guile")))
>
>(define haunt-the-ghost
>  (package
>    (inherit haunt)
>    (name "haunt-for-guix-website")
>    (inputs
>     `(("guile" ,the-good-guile)
>       ,@(alist-delete "guile" (package-inputs haunt))))))
>--8<---------------cut here---------------end--------------->8---
>
>and the file .guix.scm contains
>
>--8<---------------cut here---------------start------------->8---
>(define latest-guix
>  ;; The latest Guix.  Using it rather than the 'guix' package ensures we
>  ;; build the latest package list.
>  (latest-channels %default-channels))
>
>(define (inferior-package spec)
>  (first (lookup-inferior-packages
>          (inferior-for-channels
>           (latest-channels-channels latest-guix))
>          spec)))
>
>;; Make sure that Haunt uses the same Guile as the one from
>;; "latest-guix". Otherwise there could be a mismatch between the Guile
>;; revision used by Haunt and the one from the latest Guix modules used by
>;; Haunt.
>(define haunt-with-latest-guile
>  (package
>    (inherit haunt)
>    (inputs
>     `(("guile" ,(inferior-package "guile"))
>       ,@(package-inputs haunt)))))
>--8<---------------cut here---------------end--------------->8---
>
>so it should be the same Haunt.  I mean, there is no gap between the
>version of Guile of latest-guix and the package guix.  But, I am missing
>something because the failure comes from:
>
>--8<---------------cut here---------------start------------->8---
>(invoke #+(file-append haunt-with-latest-guile
>                       "/bin/haunt")
>       "build")
>--8<---------------cut here---------------end--------------->8---
>
>It requires some investigations. :-)
>
>
>Cheers,
>simon