Fixed in master (of libgpg-error).
Pushed the change to libgcrypt (master and 1.10 branch).

works in gnupg24.

works

I'd say yes.

The "Secret key backup error" does not appear any more.
But if I hit "cancel" on the pinentry window, still a second pinentry window for the subkey pops up. No matter if I give the correct password in the second pinentry window or not, the backup is silently abandoned.

Thank you for the bug report.

We need to extend dirmngr_ldap.c to take a list of attributes to return. We already have the --multi option which returns all attributes for latter filtering by the caller but the specified attr is also used and thus dirmngr's start_cacert_fetch_ldap() retruns only the requested caCertificate.

Things for 2.4 are all done.

For 2.2 we will for now only implement the encryption.

yes, confirmed. And if I insist on choosing this certificate via the selection dialog I can not encrypt to this certificate, as sign/encrypt is grayed out. (As long as there is no valid key chosen additionally.)

@gniibe: Would you mind to look at this?

closing with reference to external testing

ok, ticket for the new issue is T6418

README and INSTALL now suggest to to use a build directory.

Error checking of the parameter file is usually enhanced when adding new features. Keeping this task open for this specific request does not make sense,

Not sure why this was assigned to Andre.

In T5543#168681, @ebo wrote:

How about emptying both fields in case of mismatch and start from the beginning?

This exact step works. But if you misspell the repeat its unintuitive again what you should do.

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing with reference to external testing

closing and opening new tasks is the best option

Turned out to be a bit come complicated. I hope that I did not break any of the other pinentries:
rP8ab1682e80a2b4185ee9ef66cbb44340245966fc

This header was introduced close to 20 years ago. I agree that it does not make any sense - it might be a left-over from an old Hurd version. We can entirely remove it because string.h is already included and we also don't use memory.h anywhere in gnupg proper.

gpg-agent now supports READKEY --card command which creates stub file when it's not yet available on host computer.
It was implemented by rG82cbab906a3e: agent: Add --card option for READKEY.