This one requires a bit of jumping through hoops. Patching the dtd /
catalog lookup is quite straightforward and similar to cxml, but the
CLOSURE-HTML:*html-dtd* variable gives us a bit of trouble: It is
defined quite late in `html-parser.lisp`, but files that need to be
built first already reference it. SBCL has apparently decided to be
particular about this and emits a `WARNING` (!) condition for this
which is also worthy of `failure-p` of `compile-file` being true,
so that `buildLisp` will abort compilation. We workaround this issue
by injecting an extra source file which `defvar`s the desired symbol.
A similar issue exists with `dump-dtd` which references
`CL-USER:*HTML-DTD*` for some reason. Since this is a helper intended
for development (?) and not exported we just throw it away via a
patch.
Change-Id: Ic0f92815a21f3793925c49a70a72f4a86791efe4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3263
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>