Fix typo in CMakeList.

[rhubner]

Fix #12237

[adamretter]

I think a small fix is still needed in Findzstd.cmake.
It might also be worth checking the other files in cmake/modules/ as well?

[adamretter]

I think this also needs fixing in cmake/modules/Findzstd.cmake where it seems to be in mixed-case.

[adamretter]

Now LGTM. Thanks @rhubner

[adamretter]

@ajkr @pdillinger Can we get this one imported please?

[facebook-github-bot]

@ajkr has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@ajkr merged this pull request in 054c00e.

[georgthegreat]

This PR broke nixpkgs build. It looks like their version of zstd does not export ZSTD_INCLUDE_DIRS

[rhubner]

Hello @georgthegreat,

This PR broke nixpkgs build. It looks like their version of zstd does not export ZSTD_INCLUDE_DIRS

Can you please provide more details? Link to CI/CD, reported issue in nixpkgs, ...

Radek

[georgthegreat]

We have an internal system built atop of nixpkgs.
I am receiving the following error from it:

-- Found assembler: /nix/store/90h6k8ylkgn81k10190v5c9ldyjpzgl9-gcc-wrapper-12.3.0/bin/gcc
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /nix/store/90h6k8ylkgn81k10190v5c9ldyjpzgl9-gcc-wrapper-12.3.0/bin/g++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /nix/store/90h6k8ylkgn81k10190v5c9ldyjpzgl9-gcc-wrapper-12.3.0/bin/gcc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Found ZLIB: /nix/store/8xgb8phqmfn9h971q7dg369h647i1aa0-zlib-1.3/lib/libz.so (found version "1.3")
-- Found BZip2: /nix/store/155qsyx1mv11fsi48nz4dlc0vh1a3drx-bzip2-1.0.8/lib/libbz2.so (found version "1.0.8")
-- Looking for BZ2_bzCompressInit
-- Looking for BZ2_bzCompressInit - found
-- Found lz4: /nix/store/874gxh0sgwkbwb7nfbp72sn7a058b7sa-lz4-1.9.4/lib/liblz4.so
CMake Error at /nix/store/vnhl4zdy7igx9gd3q1d548vwzz15a9ma-cmake-3.27.7/share/cmake-3.27/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
  Could NOT find zstd (missing: ZSTD_INCLUDE_DIRS)
Call Stack (most recent call first):
  /nix/store/vnhl4zdy7igx9gd3q1d548vwzz15a9ma-cmake-3.27.7/share/cmake-3.27/Modules/FindPackageHandleStandardArgs.cmake:600 (_FPHSA_FAILURE_MESSAGE)
  cmake/modules/Findzstd.cmake:17 (find_package_handle_standard_args)
  CMakeLists.txt:167 (find_package)

I have worked it around by adding the following:

  cmakeFlags = attrs.cmakeFlags ++ [
    # Configuration fails otherwise as ZSTD_INCLUDE_DIRS is checked instead of ZSTD_INCLUDE_DIR
    "-DZSTD_INCLUDE_DIRS=${zstd.dev}"
  ];

I am not quite familiar with cmake internals to debug this.

[rhubner]

@georgthegreat Thanks for quick response, I will look into at the end of the week. It's possible there is still bug which we introduce during refactoring.

Radek

[rhubner]

Hello @georgthegreat and sorry for late reply,

Unfortunately I don't know nixos, but I can confirm that we recently changed the CMake build script. The refactor follows the pattern which we used to specify include dir for other libraries. Your fix with "-DZSTD_INCLUDE_DIRS=${zstd.dev}" makes sense and sounds legit for me. What I don't understand, how did you build it before without providing libzstd include path.

About CMake. During the build script generation with CMake, you can specify path where you have your libzstd. This allows you to use your version of zstd and not for example system/distribution version. I assume that when you are building nixos, you also build libzstd and then CMake needs to know where it is, if it's not in the default search path.

Radek

[georgthegreat]

I have tried to understand why previous version worked, but I was unable to get to the root of it.
It looks like CMake's find_package does not provide any include-related variables out of the box, so it is up to the specific package manager to decide whether to provide this variables and how to name them.

I agree that -DZSTD_INCLUDE_DIRS solution solves the problems.
I am fine with keeping it.