I just upgraded to 20.09 from 20.03. Now, by default, whenever I reboot, the default bootloader entry that’s selected is “NixOS [test]”, not the generation I’ve most recently switched to. See photo of boot screen just after POST:
I’ve never seen that before
did you do
nixos-rebuild switch -p test
if you wanted to get rid of it, you can boot up into the newer profile, ensure everything works as intended, then run:
sudo nix-collect-garbage -d
This will clean up other generation such as test
NOTE: this will remove anything that doesn’t have gcroots.
the code that generates the bootloader menu’s is here.
I can’t see anything that would generate
NixOS [test]
Its seems to generate
NixOS - Profile 'test'
if you do
nixos-rebuild switch -p test
strange?
hang on , maybe it’s this piece of code… not quite sure what conditions that needs to run without more debugging…
f.write(BOOT_ENTRY.format(profile=" [" + profile + "]" if profile else "",
generation=generation,
kernel=kernel,
initrd=initrd,
kernel_params=kernel_params,
description=describe_generation(generation_dir)))
profile gets populated from
def get_profiles():
if os.path.isdir("/nix/var/nix/profiles/system-profiles/"):
return [x
for x in os.listdir("/nix/var/nix/profiles/system-profiles/")
if not x.endswith("-link")]
else:
return []
/nix/var/nix/profiles/system-profiles/
what do you have in there?
1 Like
No, I didn’t use -p test.
Interesting - I have only links to test profiles in there, but I don’t remember them showing up in the boot menu before, or if they did, they were never selected as the default:
$ ls -lA /nix/var/nix/profiles/system-profiles/
total 4
lrwxrwxrwx 1 root root 11 Aug 29 2017 test -> test-1-link
lrwxrwxrwx 1 root root 84 Aug 29 2017 test-1-link -> /nix/store/6dv22g21pg7mc89mrx641g6mj5g6rljg-nixos-system-knuth-17.03.1775.56da88a298
Are links in /nix/var/nix/profiles/system-profiles/ gcroots? Maybe that’s why they’re not gone despite being years old.
It is quite likely that you, or someone created a test profile on
Aug 29 2017
it maybe that for some reason 17.03 didn’t update the boot loader menu with optional profiles.
I doubt that alternative profiles will get garbage collected , while the test profile has a link in there.
Why it wasn’t showing up before is a mystery, is /boot full? or your boot loader partition was somehow locked read only , or not mounted correctly?
Yeah, I know I must have created the test profile at some point in the past. I deleted the test profile and now my normal profile is selected in the boot menu by default, like before.
I wonder if there’s a way to designate one generation as the default entry in the boot menu. I don’t remember switching to the test profile at any point - I presume that switching to a profile using nixos-rebuild switch also makes it the default boot menu entry.