I'm having what seems to be an issue with gpg-agent. I am trying to call gpg from a backup script via the following command:

gpg --quiet --batch --for-your-eyes-only --no-tty --decrypt [file]

Yet when the script from from cron, gpg reports the following error in the log:

gpg: using character set 'utf-8'
# off=0 ctb=85 tag=1 hlen=3 plen=524
:pubkey enc packet: version 3, algo 1, keyid 146694F411D7B1DA
data: [4096 bits]
gpg: public key is 146694F411D7B1DA
gpg: using subkey 146694F411D7B1DA instead of primary key 52933AE5BC1A10E8
gpg: pinentry launched (26320 gnome3:curses 1.1.0 - - -)
# off=527 ctb=d2 tag=18 hlen=2 plen=126 new-ctb
:encrypted data packet:
length: 126
mdc_method: 2
gpg: decryption failed: No secret key

I'm using a subkey to encrypt the file gpg is trying to decrypt, but using the main makes no difference. The script runs perfectly fine from the command line. I have this same setup on my laptop which runs MX Linux and has no problems running the script from cron. On my MX Linux laptop running the following command gets me:

ps aux | grep gpg-agent
/usr/bin/gpg-agent --sh --daemon --write-env-file /home/mx_user/.cache/gpg-agent-info

However on my Devuan box I get nothing returned. I must use sudo if order to see the process, and its owner is not root.

sudo ps aux | grep gpg-agent
gpg-agent --homedir /home/devuan_user/.gnupg --use-standard-socket --daemon

I'm not sure if this is related to the issue of gpg not working correctly in cron, but I beleive I have the appropriate options in the gpg command.

Any ideas of what might be wrong here?