+GPG=gpg
+# Choose the proper version of gpg, so as to avoid a
+# "gpg-agent is not available in this session" error
+# when gpg-agent is version 3 but gpg is still version 1.
+# FIXME-2020: remove, once all major distros ship gpg version 3 as /usr/bin/gpg
+gpg_agent_version=`(gpg-agent --version) 2>/dev/null | sed -e '2,$d' -e 's/^[^0-9]*//'`
+case "$gpg_agent_version" in
+ 2.*)
+ gpg_version=`(gpg --version) 2>/dev/null | sed -e '2,$d' -e 's/^[^0-9]*//'`
+ case "$gpg_version" in
+ 1.*)
+ if (type gpg2) >/dev/null 2>/dev/null; then
+ # gpg2 is present.
+ GPG=gpg2
+ else
+ # gpg2 is missing. Ubuntu users should install the package 'gnupg2'.
+ echo "WARNING: Using 'gpg', which is too old. You should install 'gpg2'." 1>&2
+ fi
+ ;;
+ esac
+ ;;
+esac
+
+GPG="${GPG} --batch --no-tty"