FetchContent installation

[HealthyPear]

I am following the instructions from the documentation at the Using Fetchcontent section.

I created a CLI11.cmake file within a cmake subdirectory within my top-level directory containing,

include(FetchContent)
FetchContent_Populate(
    cli11_proj
    QUIET
    GIT_REPOSITORY https://github.com/CLIUtils/CLI11.git
    GIT_TAG v2.3.2
    SOURCE_DIR cli11_proj
)

FetchContent_MakeAvailable(cli11_proj)

then from my top-level CMakeLists.txt I include it with include(cmake/CLI11.cmake).

My project is made of an executable and a library, the executable is the only one using CLI11. It lives in a cli subdirectory containing the following CMakeLists.txt (also included by the top-level one), I am doing this as per instructions

add_subdirectory(${cli11_proj_SOURCE_DIR} ${cli11_proj_SOURCE_DIR}/build)
target_link_libraries(my_exe CLI11::CLI11)

and I get this error during the configuration step,

CMake Error at /usr/local/Cellar/cmake/3.28.1/share/cmake/Modules/FetchContent.cmake:1221 (message):
  No content details recorded for cli11_proj
Call Stack (most recent call first):
  /usr/local/Cellar/cmake/3.28.1/share/cmake/Modules/FetchContent.cmake:1740 (__FetchContent_getSavedDetails)
  /usr/local/Cellar/cmake/3.28.1/share/cmake/Modules/FetchContent.cmake:2033 (FetchContent_Populate)
  cmake/CLI11.cmake:10 (FetchContent_MakeAvailable)
  CMakeLists.txt:21 (include)

What am I missing?