CPM Error generating JUCE project using CMake & CPM

CMake
1

I’m new to CMake & CPM, and attempting to get started with using them to generate JUCE projects.

My CMakeLists.txt:

cmake_minimum_required(VERSION 3.22)

project(metronome)

set(CMAKE_CXX_STANDARD 23)

set(LIB_DIR ${CMAKE_CURRENT_SOURCE_DIR}/libs)
include(cmake/get_cpm.cmake RESULT_VARIABLE ret)
message("include get_cpm successful? ${ret}")

include(libs/cpm/CPM_0.40.8.cmake RESULT_VARIABLE ret)
message("include cpm directly from CMakeLists successful? ${ret}")

CPMAddPackage(
    NAME JUCE 
    GITHUB_REPOSITORY juce-framework/JUCE 
    GIT_TAG 8.0.6
    VERSION 8.0.6
    SOURCE_DIR ${LIB_DIR}/juce
)

My slightly modified get_cpm.cmake:

# SPDX-License-Identifier: MIT
#
# SPDX-FileCopyrightText: Copyright (c) 2019-2023 Lars Melchior and contributors

set(CPM_DOWNLOAD_VERSION 0.40.8)

set(CPM_DOWNLOAD_LOCATION "${LIB_DIR}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")

# Expand relative path. This is important if the provided path contains a tilde (~)
get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)

file(DOWNLOAD
     https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
     ${CPM_DOWNLOAD_LOCATION}
)

include(${CPM_DOWNLOAD_LOCATION} RESULT_VARIABLE ret)
message("include CPM from get_cpm.cmake successful? ${ret}")

And the result of execution:

D:\Code\Plug-ins\metronome> cmake -G "MinGW Makefiles" -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -S . -B build
include CPM from get_cpm.cmake successful? D:/Code/Plug-ins/metronome/libs/cpm/CPM_0.40.8.cmake
include get_cpm successful? D:/Code/Plug-ins/metronome/cmake/get_cpm.cmake
include cpm directly from CMakeLists successful? D:/Code/Plug-ins/metronome/libs/cpm/CPM_0.40.8.cmake
CMake Error at CMakeLists.txt:14 (CPMAddPackage):
  Unknown CMake command "CPMAddPackage".


-- Configuring incomplete, errors occurred!

CPM seems to be successfully downloaded and included, and when I inspect the CPM_0.40.8.cmake file, I can see that a function definition for “CPMAddPackage” is in there.

# Download and add a package from source
function(CPMAddPackage)
   ...

Anyone know why I might be seeing “Unknown CMake command” when attempting to invoke it?

2

haven’t solved get_cpm, but directly downloading via:

# download CPM.cmake
file(
  DOWNLOAD
  https://github.com/cpm-cmake/CPM.cmake/releases/download/v0.40.8/CPM.cmake
  ${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake
  EXPECTED_HASH SHA256=78ba32abdf798bc616bab7c73aac32a17bbd7b06ad9e26a6add69de8f3ae4791
)
include(${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake)

from the cpm tutorials works for me for now.

1 Like
3

I do it like this:

Download CPM.cmake and store it in my repo in a cmake folder in my project root.

Then

# CPM.cmake
set(CPM_SOURCE_CACHE "${CMAKE_SOURCE_DIR}/Cache" CACHE PATH "Directory where downloaded dependencies will be cached")
include(cmake/CPM.cmake)

CPMAddPackage(NAME JUCE
        GITHUB_REPOSITORY juce-framework/JUCE
        GIT_TAG 8.0.6)
1 Like