Hello!
Some time ago I have made a backup of my secret key and all the
subkeys, and then deleted by-hand the master secret key by

	rm ~/.gnupg/private-keys-v1.d/[keygrip].key

The subkeys were moved to a yubikey. Everything was great. Now I wanted
to import my master key for a moment... and here we have a problem.
Right now what happens, after running

gpg --import secret_key.asc

is:

1) gpg complains:

gpg: key D444252908A80B6D: "sxrmn" not changed
gpg: key D444252908A80B6D/D444252908A80B6D: error sending to
agent: Invalid argument
gpg: key D444252908A80B6D: secret key imported
gpg: Total number processed: 1
gpg: unchanged: 1
gpg: secret keys read: 1
gpg: secret keys unchanged: 1

2) gpg -K is aware of the master secret key, though it says it's not
there:

sec#  ed25519 2022-07-06 [SC]
902404424B39514B6126A2F2D444252908A80B6D
uid    [   absolutne   ] sxrmn
ssb>  cv25519 2022-07-06 [E]
ssb>  ed25519 2022-07-06 [S]

3) seret subkeys get imported (now they are back on yubikey, but they
got imported OK)

For reference, the exactly same file on FreeBSD gets imported with no
errors at all. "diff" tells, that key exported from FreeBSD is no
different from the one I try to import to Gentoo. Therefore I guess
it's more a local GPG version problem than problem with the key.
Strangely though I am trying to import the key generated on Gentoo, so
it seems GPG can't import it's own child.

There are however some version differences between FreeBSD and Gentoo.

FreeBSD:
$ gpg --version
gpg (gnuPG) 2.3.3
libgcrypt 1.9.4
Copyright (c) 2021 Free Software Foundation, Inc.
....

Gentoo:
$ gpg --version
gpg (GnuPG) 2.2.35
libgcrypt 1.9.4-unknown
Copyright (C) 2022 g10 Code GmbH
...

So... any ideas why this happens and what can I do about it?

-- 
xWK