Chroot is a way to change the root directory of a running Linux system. This means that you can access and manipulate files on a Linux installation as if you were logged into that system, even if you are actually running a different operating system.
mkdir /mnt/rebornos
lsblk
Find the partition your system is installed on generally this is the largest partition on SDA
in this example that would be sda2 as we want to mount the / partition
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 512M 0 part /boot/efi
├─sda2 8:2 0 128G 0 part /
├─sda3 8:3 0 256.6G 0 part /home
└─sda4 8:4 0 546.2G 0 part /mnt/data
Where sdaX is the result you find in LSBLK in the above example that was sda2
mount /dev/sdaX /mnt/rebornos
chroot /mnt/rebornos /bin/bash
Now if everything went well you're in your RebornOS installation from here you can troubleshoot the issues on your system or revert breaking changes.