Build failure on Debian #2

I'm not sure it is a bug, but I am having hard time compiling libmodem.

To reproduce,

• cd libmodem/libmodem/
• mkdir build
• cd build
• cmake ..

And I have this:

[ 11%] Performing download step (git clone) for 'fmt-populate'
Cloning into 'fmt-src'...
fatal: invalid reference: master
CMake Error at fmt-subbuild/fmt-populate-prefix/tmp/fmt-populate-gitclone.cmake:61 (message):
Failed to checkout tag: 'master'

gmake[2]: *** [CMakeFiles/fmt-populate.dir/build.make:102: fmt-populate-prefix/src/fmt-populate-stamp/fmt-populate-download] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:87: CMakeFiles/fmt-populate.dir/all] Error 2
gmake: *** [Makefile:91: all] Error 2

CMake Error at /usr/share/cmake-3.31/Modules/FetchContent.cmake:1918 (message):
Build step for fmt failed: 2
Call Stack (most recent call first):
/usr/share/cmake-3.31/Modules/FetchContent.cmake:1609 (__FetchContent_populateSubbuild)
/usr/share/cmake-3.31/Modules/FetchContent.cmake:2145:EVAL:2 (__FetchContent_doPopulation)
/usr/share/cmake-3.31/Modules/FetchContent.cmake:2145 (cmake_language)
/usr/share/cmake-3.31/Modules/FetchContent.cmake:2384 (__FetchContent_Populate)
CMakeLists.txt:54 (FetchContent_MakeAvailable)