Running the following command as root worked with gnupg-2.0.26 but fails with gnupg-2.1:

  gpg --homedir /etc/pacman.d/gnupg/ --recv-keys 941C2A25

The error is:

  gpg: connecting dirmngr at '/root/.gnupg/S.dirmngr' failed: IPC connect call failed
  gpg: keyserver receive failed: No dirmngr

The issue seems to be that converting the keyring from the old format (<2.1) to the new one (2.1)
requires dirmngr which fails to launch for some reason. However, if I run:

  dirmngr < /dev/null

or even

  gpg --recv-keys 941C2A25

(without --homedir), then this seems to initialize what is required because subsequent runs of

  gpg --homedir /etc/pacman.d/gnupg/ --recv-keys 941C2A25

to work.

Is there a clean solution to this migration problem?