In reply to @emilazy:matrix.org
that's not so bad

In reply to @emilazy:matrix.org
welcome to the worst string syntax in the universe!

In reply to @emilazy:matrix.org
just putting this here to scare you ''''\'''${a}''

let bashFoo = "\${foo}"; in ''
  echo "${bashFoo}"
'';

If it's a large enough block of text to justify it, you can always put it in a separate file and readFile it. If you also need to include a handful of nix vars/expressions in the string, you could map them to bash vars using lib.toShellVars:

{
  env = {
    foo = "bar";
    sum = 1 + 2;
    hello = lib.getExe pkgs.hello;
    PATH = lib.makeBinPath [
      pkgs.git
      pkgs.cowsay
    ];
  };

  text = ''
    ${lib.toShellVars env}
    export PATH

    ${builtins.readFile ./script.sh}
  '';
}

If it's a large enough block of text to justify it, you can always put it in a separate file and readFile it. If you also need to include a handful of nix vars/expressions in the string, you could map them to bash vars using lib.toShellVars:

rec {
  env = {
    foo = "bar";
    sum = 1 + 2;
    hello = lib.getExe pkgs.hello;
    PATH = lib.makeBinPath [
      pkgs.git
      pkgs.cowsay
    ];
  };

  text = ''
    ${lib.toShellVars env}
    export PATH

    ${builtins.readFile ./script.sh}
  '';
}

I don't think I really understand tryEval:

$ nix-instantiate --strict --eval --expr 'builtins.tryEval (builtins.elemAt [] 1)'
error:
       … while calling the 'tryEval' builtin
         at «string»:1:1:
            1| builtins.tryEval (builtins.elemAt [] 1)
             | ^

       … while calling the 'elemAt' builtin
         at «string»:1:19:
            1| builtins.tryEval (builtins.elemAt [] 1)
             |                   ^

       error: list index 1 is out of bounds

What makes some error able to be tryEval'd away and what makes it not able to be?

I'd have to refer to documentation to give the exact answer, but it depends on how the error was produced.

For example throw can be "caught" by tryEval, but I believe abort cannot.

I'd expect most errors (e.g. failed assert statements) to be the equivalent of a throw rather than an abort.

I have

lib.attrsets.genAttrs [ "nix-inspect" "nixvim-config" "bundix" "feedback" "talon" "rime" "nix-ld-rs" "devenv" ] (name: "input
s.${name}.packages.x86_64.default")
{
  bundix = "inputs.bundix.packages.x86_64.default";
  devenv = "inputs.devenv.packages.x86_64.default";
  feedback = "inputs.feedback.packages.x86_64.default";
  nix-inspect = "inputs.nix-inspect.packages.x86_64.default";
  nix-ld-rs = "inputs.nix-ld-rs.packages.x86_64.default";
  nixvim-config = "inputs.nixvim-config.packages.x86_64.default";
  rime = "inputs.rime.packages.x86_64.default";
  talon = "inputs.talon.packages.x86_64.default";
}

but I want the attrs on the rhs to be attributes not just strings.

How would I achieve that ?

In reply to @emilazy:matrix.org
just drop the quotes