Can’t log into NixOS after Install!

You thought everything went well with your NixOS install, you reboot, enter your username and password, and bam! Login incorrect.

Okay, try it again.

Login incorrect


Let’s try root. Nope, same thing…

If you don’t enter the password in correctly for root at the end of an installation, there will not be a root password, hence you can not log in.

Best way to keep this from happening is to make sure the password is set up before rebooting.

If you are one of those unfortunate souls who entered the wrong root password and missed the warning at the end of the installation

Try the following.

nixos-enter --root '/mnt'

Note: If you already rebooted, boot up on the minimum USB drive, mount the root partition, then run the nixos-enter command.

mount /dev/disk/by-label/nixos /mnt
nixos-enter --root '/mnt'

passwd to set the root password. You can also set your user password with

passwd username

Change username to your username.

Reboot and login!

Set Bash as users default shell

You can change the default shell for a Linux user with the following command.  Change “/bin/bash” to whatever shell you want and replace USERNAME with the Linux user.

chsh /bin/bash USERNAME

Enter in the users password and then log out and back in and the users shell will be whatever shell you specified.  In this case bash.

You can also do this by manually editing the /etc/passwd file.  Find the user by their username, and then replace the last part of the line with the new shell path.

Some Linux distributions (like Kali Linux) use /bin/sh as the default shell for new users.  Changing it to bash makes the shell a little more usable.