flakes: nix develop: derivation ... has incorrect output ..., should be ...

[FRidh]

Describe the bug
Using 2.4pre20200622_334e26b from Nixpkgs I get the following when using nix develop on a Flake where the derivation accessed has multiple outputs.

Steps To Reproduce

$ nix develop
error: --- Error ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- nix
error: --- Error --- nix-daemon
derivation '/nix/store/yjxddymbpgcclrfimqryjcyxjqii0sp0-python3.8-vibro-dev-env.drv' has incorrect output '/nix/store/s13ck6m19fcfmz1whnli5kbf701dg73z-python3.8-vibro-dev-doc', should be '/nix/store/ldbn5g2ybkrmafilknxwbrz0b8771agw-python3.8-vibro-dev-env-doc'

Removing the multiple outputs, leaving only "out" works around the issue.

I also tried with

/nix/store/0czaqb3a461q886xwagjky01pxs7p6y4-nix-2.4pre20200629_26cf0c6/bin/nix

but that led to a core dump.

Expected behavior

nix-env --version output

[FRidh]

Older occurrence of the error #2315
Supposedly fixed in aef635d.

[FRidh]

Judging from the lines changed in the previous fix and what has changed there I imagine it is related to 2f0e395 and thus #3649.

Actually, no. That was not yet merged in Nix at 334e26b.

[FRidh]

When using develop on a nixpkgs.mkShell I get

error: stack overflow (possible infinite recursion)

[FRidh]

When having an inputsFrom in mkShell the error is

querying info about missing pathserror: stack overflow (possible infinite recursion)

[FRidh]

Fixed with 68f524d.