Well, I’m working on a C++ project where I am using linear algebra from Eigen.
This is how I fetch the Eigen library from my root CmakeLists.txt:
message([STATUS] "Fetching eigen.")
block(SCOPE_FOR VARIABLES)
set(EIGEN_BUILD_TESTING OFF)
set(EIGEN_BUILD_PKGCONFIG OFF)
set(EIGEN_BUILD_DOC OFF)
FetchContent_Declare(
Eigen
GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
GIT_TAG 3.4
GIT_SHALLOW TRUE
GIT_PROGRESS TRUE
)
FetchContent_MakeAvailable(Eigen)
endblock()
I then have github actions to build and test on both ubuntu-22.04 and windows-latest.
The instructions to build on windows are (copied only until build starts):
# This starter workflow is for a CMake project running on a single platform. There is a different starter workflow if you need cross-platform coverage.
# See: https://github.com/actions/starter-workflows/blob/main/ci/cmake-multi-platform.yml
name: CMake build and test on Windows
on:
push:
branches: [ "master" ]
pull_request:
branches: [ "master" ]
env:
# Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
BUILD_TYPE: Release
jobs:
build:
name: build and test
# The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
# You can convert this to a matrix build if you need cross-platform coverage.
# See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
runs-on: windows-latest
steps:
- uses: actions/checkout@v4
- name: Set reusable strings
id: strings
shell: bash
run: |
echo "build-output-dir=${{ github.workspace }}/build" >> "$GITHUB_OUTPUT"
echo "bin-output-dir=${{ github.workspace }}/bin" >> "$GITHUB_OUTPUT"
- name: Configure CMake
run: >
cmake -B ${{ steps.strings.outputs.build-output-dir }}
-DCMAKE_CXX_COMPILER=msvc
-DCMAKE_C_COMPILER=msvc
-DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }}
-S ${{ github.workspace }}
Problem
The linux build is successful, but the windows build fails with a slightly unexpected error already at the “Configure CMake” step. The error says:
[STATUS]Fetching pugixml.
[STATUS]Fetching eigen.
-- The C compiler identification is MSVC 19.39.33523.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Tools/MSVC/14.39.33519/bin/Hostx64/x64/cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Performing Test EIGEN_COMPILER_SUPPORT_CPP11
-- Performing Test EIGEN_COMPILER_SUPPORT_CPP11 - Failed
-- Performing Test COMPILER_SUPPORT_std=cpp03
-- Performing Test COMPILER_SUPPORT_std=cpp03 - Failed
-- Performing Test standard_math_library_linked_to_automatically
-- Performing Test standard_math_library_linked_to_automatically - Failed
-- Performing Test standard_math_library_linked_to_as_m
-- Performing Test standard_math_library_linked_to_as_m - Failed
CMake Error at build/_deps/eigen-src/CMakeLists.txt:136 (message):
Can't link to the standard math library. Please report to the Eigen
developers, telling them about your platform.
-- Configuring incomplete, errors occurred!
Error: Process completed with exit code 1.
What anybody have clue?
Note:
This used to compile before I added OpenXLSX to the project as a submodule. Now it does not. The OpenXLSX library should be able to be built with msvc (which I am using), according to the official readme.
This is really weird to me.
Would it maybe help if I obtained all my packages with CPM (GitHub - cpm-cmake/CPM.cmake: 📦 CMake's missing package manager. A small CMake script for setup-free, cross-platform, reproducible dependency management.) ?
Additional question:
What is the preffered modern approach? To use CMake and fetch content or gitlab submodules?