Image is too large, so no file was created. (yes it would be nice if the system throws a simple message when this common error occurs).
I see that aircrack-ng brings in libopenssl, which is large while libwolfssl (only slightly smaller) is the default SSL library. Therefore you should change libustream and wpad to the openssl versions, so wolfssl can be left out.
Try this list:
aircrack-ng base-files busybox ca-bundle dnsmasq dropbear firewall4 fstools kmod-ath9k kmod-gpio-button-hotplug kmod-nft-offload libustream-openssl logd mtd netifd nftables opkg procd procd-seccomp procd-ujail rssileds swconfig uboot-envtools uci uclient-fetch urandom-seed urngd kernel wpad-basic-openssl luci uhttpd
- opkg, uclient-fetch, ca-bundle, and libustream are not needed if you won't be installing packages at run-time. Rebuild if you need a different package set.
- If you do keep opkg functionality, adding
aucwould be useful to automate cram-down rebuilds as I described earlier.
- wpad probably isn't needed if you are only going to run wifi in monitor mode.
- You could download the aircrack ipk, open it up (ipks are nested tar.gz files) and pick only the binaries you want and manually copy them to your CPE-- most of them probably don't need openssl.