Debian Testing Build Error: Could NOT find FFmpeg (missing: avdevice avformat) (found version "58.91.100")

[EvanCarroll]

Log from Debian Testing Bullseye

❯ mkdir build && cd build
cmake -DLIBOBS_INCLUDE_DIR="../../obs-studio/libobs" -DCMAKE_INSTALL_PREFIX=/usr ..
make -j4
sudo make install

mkdir: cannot create directory ‘build’: File exists
-- The C compiler identification is GNU 10.2.0
-- The CXX compiler identification is GNU 10.2.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- OBS_VERSION: 26.1.0-rc1-6-g96da863f
-- Found OpenGL: /usr/lib/x86_64-linux-gnu/libGL.so   
-- Found X11: /usr/include   
-- Looking for XOpenDisplay in /usr/lib/x86_64-linux-gnu/libX11.so;/usr/lib/x86_64-linux-gnu/libXext.so
-- Looking for XOpenDisplay in /usr/lib/x86_64-linux-gnu/libX11.so;/usr/lib/x86_64-linux-gnu/libXext.so - found
-- Looking for gethostbyname
-- Looking for gethostbyname - found
-- Looking for connect
-- Looking for connect - found
-- Looking for remove
-- Looking for remove - found
-- Looking for shmat
-- Looking for shmat - found
CMake Error at /usr/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:165 (message):
  Could NOT find FFmpeg (missing: avdevice avformat) (found version
  "58.91.100")
Call Stack (most recent call first):
  /usr/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:458 (_FPHSA_FAILURE_MESSAGE)
  cmake/Modules/FindFFmpeg.cmake:151 (find_package_handle_standard_args)
  deps/media-playback/CMakeLists.txt:3 (find_package)


-- Configuring incomplete, errors occurred!
See also "/tmp/obs-studio/obs-v4l2sink/CMakeFiles/CMakeOutput.log".
make: *** No targets specified and no makefile found.  Stop.
make: *** No rule to make target 'install'.  Stop.