Ghost python package

Hi,

I am trying to remove folder form /nix/store.

$ nix-store --delete /nix/store

/nki9ywqzbvz68vr75kn2r7g1q84f5agy-python3-3.9.6
finding garbage collector roots…
0 store paths deleted, 0.00 MiB freed
error: cannot delete path ‘/nix/store/nki9ywqzbvz68vr75kn2r7g1q84f5agy-python3-3.9.6’ since it is still alive

$ nix-store -q --roots /nix/store/nki9ywqzbvz68vr75kn2r7g1q84f5agy-python3-3.9.6

nix-store -q --roots /nix/store/nki9ywqzbvz68vr75kn2r7g1q84f5agy-python3-3.9.6
/nix/var/nix/profiles/per-user/dan/profile-60-link → /nix/store/2i7qhj5x9pi5a5xadxbiyx1n6faqyww6-user-environment

I see that I am using it in my current environment,
but I cannot find python among installed apps

$ nix-env --query | grep python | wc -l
0

There is no ref to python3.9:

find  /nix/store/2i7qhj5x9pi5a5xadxbiyx1n6faqyww6-user-environment -name '*python*'
/nix/store/2i7qhj5x9pi5a5xadxbiyx1n6faqyww6-user-environment/lib/python3.8

Could you try

grep -R /nix/store/nki9ywqzbvz68vr75kn2r7g1q84f5agy-python3-3.9.6
 /nix/store/2i7qhj5x9pi5a5xadxbiyx1n6faqyww6-user-environment

And

nix why-depends  /nix/store/2i7qhj5x9pi5a5xadxbiyx1n6faqyww6-user-environment /nix/store/nki9ywqzbvz68vr75kn2r7g1q84f5agy-python3-3.9.6