Short guide on how to bypass this:
If you haven't disabled rootfs verification, switch to vt-2 and run /usr/libexec/debugd/helpers/dev_features_rootfs_verification. Then reboot.
Inside crostini, download minioverride.c and compile it with gcc minioverride.c -o minioverride.so -shared (make sure gcc is installed)
In the files app, move minioverride.so into your downloads folder.