Recent versions of traditional installers Calamares and Ubiquity don't work well in the Catbird Linux live environment. Save your time and use the built-in linux-clone script. It is a tool, written in bash, which will install Grub2 (the bootloader) and copy the running Catbird Linux filesystem to the drive and partition you select. After it finishes, you will be able to boot Catbird Linux and run it as a fully installed, non compressed Linux system with full persistence.
The inner workings of the script are pretty simple. It offers you a list of partitions, from which you select the location to clone the filesystem. The script notes the location, gets the proper UUID identifying the partition, then begins using Rsync to copy the relevant files. It installs Grub2, sets up the system, then quits. The cloned system has the same settings, software, look, and feel as experienced in the live environment.