Mongocxx 4.0 weird error during build

whenever i try to build the mongocxx 4.0 driver using the instructions online on my debian 12 vm (works fine in ubuntu 22), it gives me the folllowing errors.

Please help. i have absolutely no idea why this wont work

user@debian:~/Downloads/mongo-cxx-driver-r4.0.0/build$ cmake … -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_STANDARD=17
– No MongoDB C Driver path provided via CMAKE_PREFIX_PATH, will download C driver version 1.29.0 from the internet.
– Download and configure C driver version 1.29.0 … begin
[ 11%] Performing update step for ‘mongo-c-driver-populate’
CMake Error at /home/user/Downloads/mongo-cxx-driver-r4.0.0/build/_deps/mongo-c-driver-subbuild/mongo-c-driver-populate-prefix/tmp/mongo-c-driver-populate-gitupdate.cmake:25 (message):
Failed to get the hash for HEAD:

fatal: not a git repository: ‘.git’

gmake[2]: *** [CMakeFiles/mongo-c-driver-populate.dir/build.make:130: mongo-c-driver-populate-prefix/src/mongo-c-driver-populate-stamp/mongo-c-driver-populate-update] Error 1
gmake[1]: *** [CMakeFiles/Makefile2:83: CMakeFiles/mongo-c-driver-populate.dir/all] Error 2
gmake: *** [Makefile:91: all] Error 2

CMake Error at /usr/share/cmake-3.25/Modules/FetchContent.cmake:1616 (message):
Build step for mongo-c-driver failed: 2
Call Stack (most recent call first):
/usr/share/cmake-3.25/Modules/FetchContent.cmake:1756:EVAL:2 (__FetchContent_directPopulate)
/usr/share/cmake-3.25/Modules/FetchContent.cmake:1756 (cmake_language)
/usr/share/cmake-3.25/Modules/FetchContent.cmake:1970 (FetchContent_Populate)
cmake/FetchMongoC.cmake:39 (FetchContent_MakeAvailable)
CMakeLists.txt:78 (include)

– Configuring incomplete, errors occurred!

Using a later cmake version fails differently:

– Download and configure C driver version 1.29.0 … end
CMake Warning (dev) at CMakeLists.txt:207 (find_package):
Policy CMP0148 is not set: The FindPythonInterp and FindPythonLibs modules
are removed. Run “cmake --help-policy CMP0148” for policy details. Use
the cmake_policy command to set the policy and suppress this warning.

This warning is for project developers. Use -Wno-dev to suppress it.

– Found PythonInterp: /usr/bin/python3.11 (found version “3.11.2”)
fatal: not a git repository (or any of the parent directories): .git
Traceback (most recent call last):
File “/home/user/Downloads/mongo-cxx-driver-r4.0.0/etc/calc_release_version.py”, line 370, in
RELEASE_VER = main()
^^^^^^
File “/home/user/Downloads/mongo-cxx-driver-r4.0.0/etc/calc_release_version.py”, line 325, in main
head_commit_short = check_output([‘git’, ‘rev-parse’, ‘–revs-only’,
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/home/user/Downloads/mongo-cxx-driver-r4.0.0/etc/calc_release_version.py”, line 131, in check_output
raise subprocess.CalledProcessError(ret, args[0])
subprocess.CalledProcessError: Command ‘git’ returned non-zero exit status 128.
CMake Error at CMakeLists.txt:220 (message):
BUILD_VERSION not specified and could not be calculated (script invocation
failed); specify in CMake command, -DBUILD_VERSION=

i do have git installed, and as far as i know i have no network restrictions that would prevent a git repo from being downloaded

the error seems to be saying that there isnt a git repo. i can see the source code being downloaded properly into the _deps folder. so it shouldnt be me failing to download the source