Can I somehow do nix shell nixpkgs#rust-analyzer nixpkgs#openssl nixpkgs#pkg-config github:nix-community/fenix#complete without running nix flake init first?

Basically when I have to temporarily work on Rust project that isn't flakified, I just want to get the dev env working without having some extra files checked in.

And you probably want someting like

 nix shell github:nix-community/fenix#complete.toolchain

for enix.

And you probably want someting like

 nix shell github:nix-community/fenix#complete.toolchain

for fenix.

anyone's using vscode and rust-analyzer? I've tried about a dozen configurations now and each one breaks in a new and exciting way :) what I want to have is nix shell that's capable of building a rust project and packaging it into docker with the openssl (rustls is known broken for my use case) and a working rust-analyzer so I could write the code with some LSP support. My very latest iteration was trying to use ipetkov/crane but rust-analyzer fails on that with

[ERROR rust_analyzer::lsp_utils] rust-analyzer failed to load workspace: Failed to find sysroot for Cargo.toml file /home/nixos/src/kube-cidr-manager/Cargo.toml. Is rust-src installed?: can't load standard library from sysroot
/nix/store/n7m9l6djxf3xcdc2dk9scc6rbpw825p9-rustc-1.63.0
(discovered via `rustc --print sysroot`)
try installing the Rust source the same way you installed rustc