Minimal failing exampe of CMake

README.md

Build

To provide the same testing environment as would be used in production:

$ docker pull atlas/analysisbase:21.2.114
$ docker run --rm -it -v $PWD:/code/ -w /code/ atlas/analysisbase:21.2.114 /bin/bash -c "source /release_setup.sh; bash"
# bash build.sh

build.sh

#!/usr/bin/env bash

function print_and_run () {
    printf "\n# %s\n" "${1}"
    eval $(echo "$1")
}

function setNumProcessors () {
    # Set the number of processors used for build
    # to be 1 less than are available
    if [[ -f "$(which nproc)" ]]; then
        NPROC="$(nproc)"
    else
        NPROC="$(grep -c '^processor' /proc/cpuinfo)"
    fi
    echo "$(($(nproc)-1))"
}

function build {
    cd "${baseDir}"

    if [[ -d "${baseDir}/build" ]]; then
      rm -rf "${baseDir}/build"
    fi
    print_and_run "mkdir -p build"
    print_and_run "cd build"
    print_and_run "cmake .."

    NPROC="$(setNumProcessors)"
    printf "\n# %s\n" "cmake --build . -- -j${NPROC}"
    cmake --build . -- -j${NPROC}
}

# Run program
baseDir=${PWD}
build

CMakeLists.txt

cmake_minimum_required (VERSION 3.14 FATAL_ERROR)
set(CMAKE_CXX_STANDARD 14)
project(testing_frugal)

include(FetchContent)

FetchContent_Declare(
  nlohmann_json
  GIT_REPOSITORY https://github.com/nlohmann/json.git
  GIT_TAG        v3.8.0
)
FetchContent_Declare(
  FunctionalPlus
  GIT_REPOSITORY https://github.com/Dobiasd/FunctionalPlus.git
  GIT_TAG        v0.2.7-p0
)
FetchContent_Declare(
  frugally-deep
  GIT_REPOSITORY https://github.com/Dobiasd/frugally-deep.git
  GIT_TAG        v0.14.3-p0
)

FetchContent_MakeAvailable(nlohmann_json FunctionalPlus frugally-deep) # This fails
#FetchContent_MakeAvailable(nlohmann_json FunctionalPlus) # This doesn't fail

Updating the GIT_TAGs following Dobiasd/frugally-deep#232 will cause this to no longer fail. 👍 Thanks @henryiii.