Comment 2 for bug 1169121

hey phaidros,

I was bitten by this too, on debian.
CPM uses gpgMe, which uses the agent if present.
Turns out this is due to some gpg-agent stupidity. Clearly the interface has changed a bit since 2012.

I haven't investigated how the gpg-agent daemon is started on ubuntu, but it usually started from the .xsession with an 'eval $(gpg-agent --daemon --write-env-file "${HOME}/.gpg-agent-info")' call.
writing GPG_AGENT_INFO to the environment, and also to a file ~/.gpg-agent-info file

in which case those environment variables need to be set and exported in all interactive sessions:

if [ -f "${HOME}/.gpg-agent-info" ]; then
  . "${HOME}/.gpg-agent-info"
  export GPG_AGENT_INFO
  export SSH_AUTH_SOCK
fi

(the last export for --enable-ssh-support)

hope this helps