Sops failed when "--keyservice" used ERROR: Could not load secring: open /root/.gnupg/secring.gpg

I think the issue in the https://github.com/mozilla/sops/blob/master/pgp/keysource.go line:302

func (key *MasterKey) secRing() (openpgp.EntityList, error) { return key.loadRing(key.gpgHome() + "/secring.gpg") }

but based on official GnuPG Documentation:

~/.gnupg/secring.gpg
    A secret keyring as used by GnuPG versions before 2.1. It is not used by GnuPG 2.1 and later.

~/.gnupg/secring.gpg.lock
    The lock file for the secret keyring.

https://www.gnupg.org/documentation/manuals/gnupg/GPG-Configuration.html

ERROR:

sops --keyservice tcp://127.0.0.1:5000 --enable-local-keyservice=false test1.yaml

Failed to get the data key required to decrypt the SOPS file.

Group 0: FAILED
  C2CD75E650166658638EDFBA2E3081C34794EF92: FAILED
    - | rpc error: code = Unknown desc = could not decrypt data key
      | with PGP key: golang.org/x/crypto/openpgp error: Could not
      | load secring: open /root/.gnupg/secring.gpg: no such file or
      | directory; GPG binary error: exit status 2

Recovery failed because no master key was able to decrypt the file. In
order for SOPS to recover the file, at least one key has to be successful,
but none were.

My .gnupg/ dir contain followed files:

drwx------. 2 root root   21 Nov  7 09:17 crls.d
drwx------. 2 root root  162 Nov  7 09:32 openpgp-revocs.d
drwx------. 2 root root  110 Nov  7 09:32 private-keys-v1.d
-rw-r--r--. 1 root root 8828 Nov  7 09:32 pubring.kbx
-rw-r--r--. 1 root root 6376 Nov  7 09:30 pubring.kbx~
-rw-r-----. 1 root root  676 Nov  7 09:14 sshcontrol
-rw-------. 1 root root 1440 Nov  7 09:35 trustdb.gpg

Versions:
OS: CentOS 8
SOPS: sops 3.4.0 (latest)
GnuPG: gpg (GnuPG) 2.2.9
libgcrypt 1.8.3

Start in pgp/keysource.go at MasterKey.secRing and loadRing, then reproduce the failure with the shown sops --keyservice command. Compare the key-loading path with the reported GnuPG 2.2 keyring layout. Done means decryption no longer fails because /root/.gnupg/secring.gpg is missing.