repl `:log` does not support derivation paths

[roberth]

Describe the bug

nix-repl> :log /nix/store/fiip84zv229vagk4i290f74jj383m2pf-vm-test-run-nixops-legacy-network.drv
error: expression does not evaluate to a derivation, so I can't build it

This is nonsensical in two ways, both of which should be fixed:

• It already is a derivation; no need to really evaluate.
• "I can't build it" doesn't make sense for :log. It seems that some method's error message wrongly assumes we're trying to build a derivation.

Steps To Reproduce

As above.

Expected behavior

It shows the log.

nix-env --version output

Additional context

Workaround: the "forbidden" import. Please don't use import like that.

nix-repl> :log import /nix/store/fiip84zv229vagk4i290f74jj383m2pf-vm-test-run-nixops-legacy-network.drv

Priorities

Add 👍 to issues you find important.