wrapper-common/utils.bash, gcc: @file params are not put back into an @file after expansion

[jsoo1]

Describe the bug

When a tool uses an @file to execute gcc (or any of the gnu linkers) via the wrappers, expandResponseParams undoes the @file that the tool uses. For example hsc2hs always uses @files to run linkers (see https://github.com/haskell/hsc2hs/blob/5bf5c61e7c6e813d03bc069e17289c574185d41c/src/Common.hs#L37).

But in the wrappers (via utils.bash) expandResponseParams silently expand @files and re-execs the compiler/linker without the @file in the cc/ld wrappers. See

nixpkgs/pkgs/build-support/wrapper-common/utils.bash

Line 121 in 7fb1b60

expandResponseParams() {

For example - the linker only checks NIX_LD_USE_RESPONSE_FILE here

nixpkgs/pkgs/build-support/bintools-wrapper/ld-wrapper.sh

Line 259 in 973d6eb

if (( "${NIX_LD_USE_RESPONSE_FILE:-@use_response_file_by_default@}" >= 1 )); then

even if an @file was explicitly requested by the invoking tool.

This results in E2BIG for even small hsc2hs invocations.

This would seem easy enough to fix - by setting an env var like NIX_REPONSE_FILE_EXPANDED=1 and also checking that, but it seems to break some packages (like bison and ghc itself though maybe this is fixed on staging).

Related to #41340

Steps To Reproduce

(on x86_64-linux) nix build github:awakesecurity/nixpkgs?ref=reproduce-expand-response-params#haskellPackages.termonad
See reproducing patch here: awakesecurity@97fde27

Expected behavior

@files should be restored after expanding if the original execution requested it.

Notify maintainers

@vcunat @Ericson2314 @Synthetica9

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 5.10.177, NixOS, 22.05 (Quokka)`
 - multi-user?: `yes`
 - sandbox: `relaxed`
 - version: `nix-env (Nix) 2.15.1`