doc/HACKING says it's OK to use variadic arg macros (from C99 features).
If it's OK, this patch can fix the initialization (which silences GCC 15 warnings):

Good morning,
I stumbled upon this when digging through old Debian bug reports against 1.4 and checking whether they still applied to 2.4. This one really still applies.

IIUC, it's GCC 8 which starts the support of __nonstring__ attribute.

In any case, the actual connectivity test needs to be performed by GnuPG. Otherwise we might just test whether the Qt/KDE libraries can reach versions.gnupg.org, but not whether dirmngr can. Werner proposed something like gpg --fetch-key https://gnupg.org/index.html.

Creating a new entry with the name of an existing entry will override the existing entry without warning.

Fixed.

In T5444#146395, @werner wrote:

You should anyway use --quick-gen-key.

This is still broken on 2.5.5.

Gpg4win is a community version and we may or may not apply Authenticode signatures. You can do that yourself, after having checked our OpenPGP release signature. You may however be interested in GnuPG Desktop, which comes with full support and also Authenticode signature.

This is resolved in the final Beta15.