Redirect stderr from cron

root/etc/s6-overlay/s6-rc.d/init-crontab-config/run

@@ -10,7 +10,7 @@ for cron_user in abc root; do
         # if crontabs do not exist in config
         if [[ ! -f "/config/crontabs/${cron_user}" ]]; then
             # copy crontab from system
-            if crontab -l -u "${cron_user}" >/dev/null; then
+            if crontab -l -u "${cron_user}" >/dev/null 2>&1; then
                 crontab -l -u "${cron_user}" >"/config/crontabs/${cron_user}"
             fi
 

root/etc/s6-overlay/s6-rc.d/svc-cron/run

@@ -1,8 +1,8 @@
 #!/usr/bin/with-contenv bash
 # shellcheck shell=bash
 
-if builtin command -v crontab >/dev/null && [[ -n "$(crontab -l -u abc)" || -n "$(crontab -l -u root)" ]]; then
+if builtin command -v crontab >/dev/null 2>&1 && [[ -n "$(crontab -l -u abc)" || -n "$(crontab -l -u root)" ]]; then
-    if builtin command -v busybox >/dev/null && [[ $(busybox) =~ [[:space:]](crond)([,]|$) ]]; then
+    if builtin command -v busybox >/dev/null 2>&1 && [[ $(busybox) =~ [[:space:]](crond)([,]|$) ]]; then
         exec busybox crond -f -S -l 5
     elif [[ -f /usr/bin/apt ]] && [[ -f /usr/sbin/cron ]]; then
         exec /usr/sbin/cron -f -L 5