anchor.diff: -{ stdenv, callPackage, lib, fetchurl, fetchFromGitHub
  +{ stdenv, callPackage, lib, fetchurl, fetchFromGitHub, installShellFiles
   , runCommand, runCommandCC, makeWrapper, recurseIntoAttrs
   # this package (through the fixpoint glass)
   , bazel_self
  
positive.code:   # when a command can’t be found in a bazel build, you might also
    # need to add it to `defaultShellPath`.
    nativeBuildInputs = [
      zip
      python3
      unzip
  
negative.code:     mv ./bazel_src/output/bazel $out/bin/bazel-${version}-${system}-${arch}
  
      # shell completion files
      installShellCompletion --bash \
        --name bazel.bash \
        ./bazel_src/output/bazel-complete.bash
      installShellCompletion --zsh \
        --name _bazel \
        ./bazel_src/scripts/zsh_completion/_bazel
      installShellCompletion --fish \
        --name bazel.fish \
        ./bazel_src/scripts/fish/completions/bazel.fish
    '';
  
    doInstallCheck = true;
  