rust-analyzer is ignoring "server.path" (either because of "remote" workspace, or NixOS, or both)

On NixOS, with code-server, rust-analyzer blows up before it even get a chance:

INFO [2/25/2022, 9:23:22 PM]: PersistentState: { serverVersion: undefined }
ERROR [2/25/2022, 9:23:22 PM]: Bootstrap error [Error: error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I)

       at «stdin»:2:36:

            1|
            2|             {srcStr, pkgs ? import <nixpkgs> {}}:
             |                                    ^
            3|                 pkgs.stdenv.mkDerivation {
(use '--show-trace' to show detailed location information)

	at /home/cole/.local/share/code-server/extensions/matklad.rust-analyzer-0.3.939/out/main.js:97:291
	at ChildProcess.exithandler (child_process.js:390:5)
	at ChildProcess.emit (events.js:400:28)
	at maybeClose (internal/child_process.js:1058:16)
	at Socket.<anonymous> (internal/child_process.js:443:11)
	at Socket.emit (events.js:400:28)
	at Pipe.<anonymous> (net.js:686:12)]

1. The patching that it does is rather brittle, has no escape hatch, requires NIX_PATH be set.
2. It seems that rust-analyzer.server.path is ignored when rust-analyzer is used on a remote workspace. I've done this in the past, I'm pretty sure things will just work if this were respected and used instead of the patching path.

Start by tracing the remote-workspace bootstrap that leads to the reported extension path in out/main.js, then inspect how rust-analyzer.server.path is handled. Reproduce the NixOS failure with code-server and determine whether the setting is bypassed; done means a configured server.path is honored without requiring the brittle Nix-based patching path.