flake: broken .?submodules=1

[widlarizer]

Describe the bug

I have been relying on nix build ".?submodules=1" -L to build OpenROAD.

Steps To Reproduce

Run nix build ".?submodules=1" -L

in reproducer repo

Expected behavior

I would expect behavior as it was recently, that is, for . to use the current directory as-is, and for submodules=1 to include all submodules, and therefore to find the C file. Instead you get > cc1: fatal error: just-hello-c/hello.c: No such file or directory

nix-env --version output

nix-env (Nix) 2.24.10

(on NixOS unstable)

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/get-nix-flake-to-include-git-submodule/30324/21

[widlarizer]

Adding a hash fixes this: nix build ".?submodules=1#" -L

[donn]

The hash issue is being tracked here: #6633