Running netboot with console redirect ttyS0 reports strange errors at nixos login

[CMCDragonkai]

Describe the bug

When running the netboot.x86_64-linux image in QEMU with console redirected to ttyS0, I see these 3 errors in a non-deterministic way:

<<< Welcome to NixOS 19.09beta-61689.gfedcba (x86_64) - ttyS0 >>>
The "nixos" and "root" accounts have empty passwords.

Type `sudo systemctl start sshd` to start the SSH daemon.
You then must set a password for either "root" or "nixos"
with `passwd` to be able to login.

Run `nixos-help` or press <Alt-F8> for the NixOS manual.

nixos login: nixos (automatic login)

ln: failed to create symbolic link '/home/nixos/.nix-profile': File exists
rm: cannot remove '/home/nixos/.nix-defexpr': Is a directory
ln: failed to create symbolic link '/home/nixos/.nix-defexpr/channels_root/channels': Read-only file system

But sometimes it will be:

<<< Welcome to NixOS 19.09beta-61689.gfedcba (x86_64) - ttyS0 >>>
The "nixos" and "root" accounts have empty passwords.

Type `sudo systemctl start sshd` to start the SSH daemon.
You then must set a password for either "root" or "nixos"
with `passwd` to be able to login.

Run `nixos-help` or press <Alt-F8> for the NixOS manual.

nixos login: nixos (automatic login)

ln: failed to create symbolic link '/home/nixos/.nix-profile': File exists
ln: failed to create symbolic link '/home/nixos/.nix-defexpr/channels_root/channels': Read-only file sysm

Sometimes I don't see anything. Weird errors that only occur sometimes. Not sure what's calling ln here.

This never happens (I haven't seen it) when I don't use console redirect, and with -vga std.

To Reproduce

Build the image:

:b (import (pkgs.path + "/nixos/release.nix") {}).netboot.x86_64-linux

Then run it in QEMU:

qemu-system-x86_64 \
  -smp $(nproc) \
  -m 8G \
  -nographic \
  -accel kvm \
  -device virtio-net,netdev=vmnic \
  -netdev user,id=vmnic \
  -kernel ./tmp/bzImage \
  -initrd ./tmp/initrd \
  -append "$(grep kernel ./tmp/netboot.ipxe | cut -f 3- -d ' ') console=ttyS0,115200"

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[pickfire]

I seemed to get the same issue too but without netboot.

[stale[bot]]

I marked this as stale due to inactivity. → More info