cmakeFlags cannot parse spaces

[IvarWithoutBones]

Describe the bug
The cmakeFlags array cannot parse spaces correctly, and thinks any argument after a space is a another CMake flag. I think it splits the flag on spaces upon parsing it. The flags do get printed out correctly, however they are not handled the same way.

I've tried using all kinds of different quotes, and escaping almost every single character, but nothing seemed to work.

To Reproduce
Steps to reproduce the behavior:

1. Append an space to a CMake flag. (cmakeFlags = [ "-DFoo=\"foo bar\"" ];)
2. Watch the cmakeConfigurePhase fail, as it thinks bar is an seperate flag, and it cannot find this local file.
   CMake Error: The source directory "/build/source/build/bar"" does not exist.

Expected behavior
cmakeFlags should be correctly passed to CMake, and the build should succeed.

Additional context
Note that when manually setting cmakeFlagsArray, this does work.

  preConfigure = ''
    cmakeFlagsArray=(
      $cmakeFlagsArray
      "-DFoo=\"foo bar\""
    )
  '';

When applying this flag from a nix-shell, it also succesfully parses it.

Notify maintainers
@ttuegel @LnL7

Metadata

• system: "x86_64-linux"
• host os: Linux 5.11.0, NixOS, 21.05pre271444.9816b99e71c (Okapi)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.10
• channels(root): "nixos-21.05pre271444.9816b99e71c"
• channels(ivv): "home-manager, nixpkgs-21.05pre271900.11cd34cd592"
• nixpkgs: /home/ivv/.nix-defexpr/channels/nixpkgs

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute: cmake
attribute: yuzu-{mainline,ea}

[jtojnar]

See also #112054

I would just recommend:

preConfigure = ''
  cmakeFlagsArray+=(
    "-DFoo=\"foo bar\""
  )
'';

[Et7f3]

by just looking at the source I find

nixpkgs/pkgs/development/tools/build-managers/cmake/setup-hook.sh

Line 39 in 34e1748

cmakeFlags="-DCMAKE_INSTALL_PREFIX=$prefix $cmakeFlags"

this pattern. I think bash transform array to string thus splitting get wrong. Can you modify this so everywhere cmakeFlags is used it is treated with bash array syntax. If you do push to a branch to ease review.

[jtojnar]

@Et7f3 Nixpkgs does not pass cmakeFlags as an array currently, so it will be a string no matter what you do on the bash side. We need _structuredAttrs (e.g. #85042) or work around on Nix side with BC-breaking hacks like 2e55b73.

[Netruk44]

I'm hitting this issue while trying to specify a generator for cmake. It appears to be impossible unless you want to use Ninja because most of them have spaces in them:

Generators
* Unix Makefiles               = Generates standard UNIX makefiles.
  Ninja                        = Generates build.ninja files.
  Ninja Multi-Config           = Generates build-<Config>.ninja files.
  Watcom WMake                 = Generates Watcom WMake makefiles.
  Xcode                        = Generate Xcode project files.
  CodeBlocks - Ninja           = Generates CodeBlocks project files.
  CodeBlocks - Unix Makefiles  = Generates CodeBlocks project files.
  CodeLite - Ninja             = Generates CodeLite project files.
  CodeLite - Unix Makefiles    = Generates CodeLite project files.
  Eclipse CDT4 - Ninja         = Generates Eclipse CDT 4.0 project files.
  Eclipse CDT4 - Unix Makefiles= Generates Eclipse CDT 4.0 project files.
  Kate - Ninja                 = Generates Kate project files.
  Kate - Unix Makefiles        = Generates Kate project files.
  Sublime Text 2 - Ninja       = Generates Sublime Text 2 project files.
  Sublime Text 2 - Unix Makefiles
                               = Generates Sublime Text 2 project files.

Attempting to specify -G"Unix Makefiles" always fails:

CMake Error: Could not create named generator "Unix

[wolfgangwalther]

Since 34a2b7a the cmake setup hooks support spaces in cmakeFlags etc., if you set __structuredAttrs = true;.