ccacheStdenv cannot find libcxx on Darwin

[mnacamura]

Issue description

The title says it all. I ran this on Darwin:

#!/usr/bin/env nix-shell --pure

with import <nixpkgs> {};
let
  myCcacheWrapper = ccacheWrapper.override {
    extraConfig = ''
      export CCACHE_COMPRESS=1
      export CCACHE_DIR=/var/cache/ccache
      export CCACHE_UMASK=007
    '';
  };
  myStdenv = overrideCC stdenv myCcacheWrapper;
in
myStdenv.mkDerivation {
  name = "darwin-ccacheStdenv-test";
  buildInputs = [ libcxx ];
  shellHook = ''
    cat << CODE > test.cc
    #include <string>
    CODE
    $CXX -c test.cc
    exit 0
  '';
}

It succeeded. Then, I removed libcxx from buildInputs and ran it again. I saw

test.cc:1:10: fatal error: 'string' file not found
#include <string>
         ^~~~~~~~
1 error generated.

Technical details

• system: "x86_64-darwin"
• host os: Darwin 17.5.0, macOS 10.13.4
• multi-user?: no
• sandbox: no
• version: nix-env (Nix) 2.0pre5889_c287d731
• channels(mnacamura): "darwin, nixpkgs-18.03pre127302.e860b651d6e"
• nixpkgs: /Users/mnacamura/Repos/nixpkgs

[mnacamura]

Running this

#!/usr/bin/env nix-shell --pure
with import <nixpkgs> {};
stdenv.mkDerivation {
  name = "darwin-stdenv-test";
  shellHook = ''
    cat << CODE > test.cc
    #include <string>
    CODE
    echo NIX_CFLAGS_COMPILE: $NIX_CFLAGS_COMPILE
    echo NIX_LDFLAGS: $NIX_LDFLAGS
    echo NIX_CXXSTDLIB_COMPILE: $NIX_CXXSTDLIB_COMPILE
    echo NIX_CXXSTDLIB_LINK: $NIX_CXXSTDLIB_LINK
    $CXX -c test.cc
    exit 0
  '';
}

returns

NIX_CFLAGS_COMPILE: -isystem /nix/store/yd3bi1p0b7wwd0cgjwy77wh549dm5x3d-libc++-4.0.1/include -F/nix/store/69yzhzc71jhxpjg5gzddj6ifvph3fxp5-CF-osx-10.10.5/Library/Frameworks -isystem /nix/store/yd3bi1p0b7wwd0cgjwy77wh549dm5x3d-libc++-4.0.1/include -F/nix/store/69yzhzc71jhxpjg5gzddj6ifvph3fxp5-CF-osx-10.10.5/Library/Frameworks
NIX_LDFLAGS: -L/nix/store/yd3bi1p0b7wwd0cgjwy77wh549dm5x3d-libc++-4.0.1/lib -L/nix/store/yd3bi1p0b7wwd0cgjwy77wh549dm5x3d-libc++-4.0.1/lib
NIX_CXXSTDLIB_COMPILE: -isystem /nix/store/yd3bi1p0b7wwd0cgjwy77wh549dm5x3d-libc++-4.0.1/include/c++/v1
NIX_CXXSTDLIB_LINK: -stdlib=libc++

and running this

#!/usr/bin/env nix-shell --pure
with import <nixpkgs> {};
let
  myCcacheWrapper = ccacheWrapper.override {
    extraConfig = ''
      export CCACHE_COMPRESS=1
      export CCACHE_DIR=/var/cache/ccache
      export CCACHE_UMASK=007
    '';
  };
  myStdenv = overrideCC stdenv myCcacheWrapper;
in
myStdenv.mkDerivation {
  name = "darwin-ccacheStdenv-test";
  shellHook = ''
    cat << CODE > test.cc
    #include <string>
    CODE
    echo NIX_CFLAGS_COMPILE: $NIX_CFLAGS_COMPILE
    echo NIX_LDFLAGS: $NIX_LDFLAGS
    echo NIX_CXXSTDLIB_COMPILE: $NIX_CXXSTDLIB_COMPILE
    echo NIX_CXXSTDLIB_LINK: $NIX_CXXSTDLIB_LINK
    $CXX -c test.cc
    exit 0
  '';
}

returns

NIX_CFLAGS_COMPILE: -F/nix/store/69yzhzc71jhxpjg5gzddj6ifvph3fxp5-CF-osx-10.10.5/Library/Frameworks -F/nix/store/69yzhzc71jhxpjg5gzddj6ifvph3fxp5-CF-osx-10.10.5/Library/Frameworks
NIX_LDFLAGS:
NIX_CXXSTDLIB_COMPILE:
NIX_CXXSTDLIB_LINK:
test.cc:1:10: fatal error: 'string' file not found
#include <string>
         ^~~~~~~~
1 error generated.

[matthewbauer]

Yes, I think ccacheWrapper is broken right now...

[luzpaz]

can you recreate this on ccache 3.6 ?

[veprbl]

caccheStdenv was not tested on Darwin (nor with clang on Linux), so probably it never worked with them

ccacheStdenv used to work for me on darwin a few years ago.

[stale[bot]]

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[matthewbauer]

Still important

[stale[bot]]

I marked this as stale due to inactivity. → More info

[nixos-discourse]

This issue has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/tensorflow-on-20-09-mac/11931/5