nix-shell mangles options sent to nix-store

[ttuegel]

man nix-shell says:

All options not listed here are passed to nix-store --realise, except for --arg and --attr / -A which are passed to nix-instantiate.

In fact, nix-shell tries to use everything as a path that doesn't begin with --. Observe:

$ nix-shell --add-root ./result --indirect
error: getting status of `./result': No such file or directory

(I've elided the full path to ./ above for clarity.)
OK, so with Nix 1.6, I would work around this by putting quotes around "--add-root ./result". Let's try that:

$ nix-shell "--add-root ./result" --indirect
error: unknown flag `--add-root result'
Try `nix-store --help' for more information.
/run/current-system/sw/bin/nix-shell: failed to build all dependencies

Alright, that's no good with Nix 1.7. The problem to begin with was that nix-shell thought result was the path to a Nix expression, and not an option for nix-store. So, I'll give it the path to an expression explicitly:

$ nix-shell default.nix --add-root ./result --indirect
error: path `./--indirect' is not a valid garbage collector root; it's not in the directory `/nix/var/nix/gcroots'
/run/current-system/sw/bin/nix-shell: failed to build all dependencies

What? Oh, ./result isn't being passed to nix-store after --add-root, even though nix-shell isn't using it as a path.

I need a way to pass arguments to nix-store through nix-shell. I suggest either or both of the following

1. Have nix-shell take only the first path on the command line as the path to a Nix expression. Leave the rest of the command line alone. Then, my third command above would work.
2. Use -- alone to terminate option parsing by nix-shell and pass everything thereafter directly to nix-store. Then I could use, e.g.,

nix-shell -- --add-root ./result --indirect