[SOLVED] CMake FetchContent Does Not Populate Name in '*_SOURCE_DIR'

Issue

I have two FetchContent actions to get two repositories. One repo works fine with the SourceDir populated. The other has an empty SourceDir. Both repos are downloaded and populated in the _deps directory.

/home/rmerriam/.local/share/JetBrains/Toolbox/apps/clion/bin/cmake/linux/x64/bin/cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_MAKE_PROGRAM=/home/rmerriam/.local/share/JetBrains/Toolbox/apps/clion/bin/ninja/linux/x64/ninja -G Ninja -S /mnt/devel/cpp_articles -B /mnt/devel/cpp_articles/cmake-build-release
    MYS_UTIL SRC_DIR    /mnt/devel/cpp_articles/cmake-build-release/_deps/mys-util-src
    TRACE_SRC_DIR   
    -- Configuring done (0.9s)
    -- Generating done (0.0s)
    -- Build files have been written to: /mnt/devel/cpp_articles/cmake-build-release
    
    [Finished]

---

The line MYS_UTIL SRC_DIR shows the directory for it. The line TRACE_SRC_DIR is blank.

Here is the CMakeLists.txt:

---

cmake_minimum_required(VERSION 3.27)
project(mys_to)
include(FetchContent)

add_compile_options(-std=c++23
        -Werror -Wpedantic -Wall -Wno-unused-variable
        -fno-exceptions -fdiagnostics-plain-output
        #        -fconcepts-diagnostics-depth=2
)

FetchContent_Declare(
        Trace
        GIT_REPOSITORY https://gitlab.com/mystic-lake-libs/Trace.git
        GIT_TAG main
        CONFIGURE_COMMAND ""
        BUILD_COMMAND ""
)
FetchContent_MakeAvailable(Trace)

FetchContent_Declare(
        mys-util
        GIT_REPOSITORY https://gitlab.com/mystic-lake-libs/mys-util
        GIT_TAG main
        CONFIGURE_COMMAND ""
        BUILD_COMMAND ""
)
FetchContent_MakeAvailable(mys-util)


message(STATUS ${mys-util_SOURCE_DIR})
message(STATUS ${Trace_SOURCE_DIR})

include_directories(${Trace_SOURCE_DIR})
include_directories(${mys-util_SOURCE_DIR})

Any suggestions on what is going wrong?

Solution

Module FetchContent defines project-related variables by prefixing them with the name of the project in lowercase. So, for the project Trace the name of the variable containing its source directory is trace_SOURCE_DIR.

Answered By - Tsyvarev

Answer Checked By - David Goodson (WPSolving Volunteer)