I am not an org-expert and cannot tell you why this is the case, but
without it the build fails with a stack trace like this one:

--8<---------------cut here---------------start------------->8---
Error: wrong-type-argument (stringp nil)
  mapbacktrace(#f(compiled-function (evald func args flags) #<bytecode -0x138225cfbe510f1c>))
  debug-early-backtrace()
  debug-early(error (wrong-type-argument stringp nil))
  string-match(\"lisp\" nil nil t)
  org-texinfo-src-block((src-block (:language nil :switches nil :parameters nil :begin 6057 :end 6527 :number-lines nil :preserve-indent nil :retain-labels t :use-labels t :label-fmt nil :value \"+--dslide-stateful-sequence\\n     +--dslide-action\\n          +--dslide-action-propertize\\n          +--dslide-action-image\\n          +--dslide-action-babel\\n          +--dslide-action-item-reveal\\n          +--dslide-action-hide-markup\\n          +--dslide-slide-action\\n               +--dslide-slide-action-every-child\\n               +--dslide-slide-action-inline\\n               +--dslide-slide-action-child\\n               +--dslide-slide-action-flat\\n\" :post-blank 0 :post-affiliated 6057 :mode nil :granularity nil :parent (section (:begin 5442 :end 6527 :contents-begin 5442 :contents-end 6527 :robust-begin 5442 :robust-end 6525 :post-blank 0 :post-affiliated 5442 :mode section :granularity nil :parent (headline (:raw-value \"
...
--8<---------------cut here---------------end--------------->8---

Unless you insist on us using your .texi file, it would be nice if you
could apply this change as well.

> The license file was also moved to COPYING.
>
> On Tue, Aug 13, 2024 at 2:20 AM Philip Kaludercic <philipk@posteo.net>
> wrote:
>
>> Psionic K <psionik@positron.solutions> writes:
>>
>> > Is anything blocked on me for dslide?
>>
>> My mail client isn't indicating that I responded to this message, so I
>> just want to make sure by saying that the package has already been added
>> to NonGNU ELPA: https://elpa.nongnu.org/nongnu/dslide.html.
>>
>> --
>>         Philip Kaludercic on peregrine
>>

Psionic K <psionik@positron.solutions> writes:

> I've bumped the version to 0.5.4.  No idea if I need to tell anyone or
> if you monitor tags on upstreams.

No, as long as you bump the "Version" header in dslide.el, then the ELPA
build server will synchronise your changes, detect the new version and
prepare new release tarballs.

> On Fri, Nov 22, 2024 at 6:11 PM Psionic K <psionik@positron.solutions> wrote:
>>
>> Hello Philip, I have gotten around to adding a proper manual to the build.
>>
>> https://github.com/positron-solutions/dslide/blob/master/doc/dslide.texi
>>
>> The license file was also moved to COPYING.
>>
>> On Tue, Aug 13, 2024 at 2:20 AM Philip Kaludercic <philipk@posteo.net> wrote:
>>>
>>> Psionic K <psionik@positron.solutions> writes:
>>>
>>> > Is anything blocked on me for dslide?
>>>
>>> My mail client isn't indicating that I responded to this message, so I
>>> just want to make sure by saying that the package has already been added
>>> to NonGNU ELPA: https://elpa.nongnu.org/nongnu/dslide.html.
>>>
>>> --
>>>         Philip Kaludercic on peregrine
>>
>>
>>
>> --
>> Only the Future is Certain

-- 
	Philip Kaludercic on siskin