Using DVD ISOs with Rolling Releases

I'm using Kali Linux for pentesting exercises. Often I find that I need to install a small utility from the repositories. Because Kali is a rolling release, and I'm not updating the OS regularly, this can mean a major update to every component of the OS when installing a minor tool. To get around this in other distributions, I've used DVD releases to keep my OS consistent to be installed from and updated by a single source. I'm trying this with Kali and I'm stuck in a loop... apt-cdrom add All good, running update apt update E: The repository 'cdrom://[Debian GNU/Linux 2019.2 _Kali-rolling_ - Official Snapshot amd64 LIVE/INSTALL Binary 20190508-10:56] kali-last-snapshot Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. vi /etc/apt/sources.list deb [trusted=yes] ... Then update again apt update E: Failed to fetch cdrom://[Debian GNU/Linux 2019.2 _Kali-rolling_ - Official Snapshot amd64 LIVE/INSTALL Binary 20190508-10:56]/dists/kali-last-snapshot/contrib/binary-i386/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs Removing the CD lines from /etc/apt.d/sources.list and trying again takes me down the same path. Does anyone know why it would to accept the CDROM as an apt source or how to troubleshoot this further? (Of course this is not for production systems or real-world exercises.)