How to nix-shell for Go projects

default.nix

# Example with go modules fetched by 
# nix and linked to the vendor directory
# when entering the shell.

with import <nixpkgs> {};

buildGoModule {
  pname = "example";
  version = "0.0.1";
  src = ./.;
  vendorSha256 = lib.fakeSha256; # to change at first build
  shellHook = ''
     eval "$configurePhase"
  '';
}

shell.nix

# Simple example with only go as dependency.
# To avoid writing in $HOME/go, we define
# the $GOPATH in a temporary location.

with import <nixpkgs> {};

mkShell {
  buildInputs = [ go ];

  shellHook = ''
     export GOCACHE=$TMPDIR/go-cache
     export GOPATH="$TMPDIR/go"
  '';
}