SDL2 missing

[samthesuperhero]

Looks like SDL2 is absent in the repo,

CMake Error at C:/Program Files/CMake/share/cmake-3.19/Modules/ExternalProject.cmake:2748 (message):
  No download info given for 'SDL2' and its source directory:

   F:/DOWNLOADS/ogre-next-deps-master/src/SDL2

  is not an existing non-empty directory.  Please specify one of:

   * SOURCE_DIR with an existing non-empty directory
   * DOWNLOAD_COMMAND
   * URL
   * GIT_REPOSITORY
   * SVN_REPOSITORY
   * HG_REPOSITORY
   * CVS_REPOSITORY and CVS_MODULE
Call Stack (most recent call first):
  C:/Program Files/CMake/share/cmake-3.19/Modules/ExternalProject.cmake:3430 (_ep_add_download_command)
  src/CMakeLists.txt:174 (ExternalProject_Add)


CMake Deprecation Warning at src/zlib/CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


Configuring incomplete, errors occurred!

[darksylinc]

Hi!

SDL2 is a subrepo, thus the repo needs to be cloned via:

git clone --recurse-submodules --shallow-submodules https://github.com/OGRECave/ogre-next-deps

Since you've already downloaded the git repo, I think the following should work:
git submodule update --init --recursive