On ubuntu rely on update-alternatives

.gnupg/gpg-agent.conf

@@ -3,6 +3,12 @@
 default-cache-ttl 21600
 max-cache-ttl 21600
 enable-ssh-support
+
+# On ubuntu use update-alternatives
+# To set the desired pinentry wrapper instead of setting pinentry-program
+
+# sudo update-alternatives --install /usr/bin/pinentry pinentry (gpgconf --list-dirs homedir)/pinentry-auto.sh 99
+
 # MUST be a full path
 # pinentry-program /usr/bin/pinentry-tty
 pinentry-program /home/USER/.gnupg/pinentry-auto.sh