Transitive dependencies ignored

[io12]

With nix-shell, all the transitive dependencies have their shell hooks run. However, with nix-buffer, only top-level dependencies affect the Emacs buffer.

For example,

NIXPKGS_ALLOW_UNFREE=1 nix-shell -p coqPackages_8_16.coq coqPackages_8_16.compcert coqPackages_8_16.HoTT --run env | grep COQPATH

outputs

COQPATH=/nix/store/y46y9afvp5knxf40jyv3np8jj1sq5r2f-coq8.16-flocq-4.1.3/lib/coq/8.16/user-contrib/:/nix/store/3lgd8ca1zsbnbdxicl714fdr8h0f70zl-coq8.16-compcert-3.13-lib/lib/coq/8.16/user-contrib/:/nix/store/rw8n88pnq598daicg8k0wwc42fv8jga0-coq8.16-HoTT-8.16/lib/coq/8.16/user-contrib/

but with this dir-locals.nix

let pkgs = import <nixpkgs> { config.allowUnfree = true; };
in pkgs.nixBufferBuilders.withPackages
(with pkgs.coqPackages_8_16; [ coq compcert HoTT ])

running (nix-buffer), waiting for the derivation to compile, and then (getenv "COQPATH") gives
:/nix/store/rw8n88pnq598daicg8k0wwc42fv8jga0-coq8.16-HoTT-8.16/lib/coq/8.16/user-contrib.

This happens because compcert.lib is a dependency of compcert.out, but isn't directly in the list passed to withPackages.

I realize that this issue is with the upstream nixBufferBuilders code in nixpkgs, but I feel like it might be easier for a fix to be upstreamed if I post the issue here instead of on the nixpkgs issue tracker.

[shlevy]

I agree this is an issue and have some rough thoughts on how to address it, but unfortunately nix-buffer is not a priority at this time. I would welcome any contributions and will be happy to review.