Bug#951087: megaglest, rbdoom3bfg, spring: FTBFS: ./obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp/./obj-x86_64-linux-gnu/CMakeFiles/CMakeTmp/src.c:11: undefined reference to `pthread_create'

[Simon McVittie]

Control: affects 951087 + megaglest rbdoom3bfg spring

On Sun, 23 Feb 2020 at 08:28:44 +0100, Lucas Nussbaum wrote:
> During a rebuild of all packages in sid, your package failed to build
> on amd64.

I think these are all <https://bugs.debian.org/951087>. From the build
log (I'm quoting from spring but the others are similar):

CMake Error at /usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:146 (message):
  Could NOT find SDL2 (missing: SDL2_INCLUDE_DIR)
Call Stack (most recent call first):
  /usr/share/cmake-3.16/Modules/FindPackageHandleStandardArgs.cmake:393 (_FPHSA_FAILURE_MESSAGE)
  rts/build/cmake/FindSDL2.cmake:194 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
  rts/builds/legacy/CMakeLists.txt:12 (FIND_PACKAGE)

Workaround: stop using FindSDL2.cmake, similar to
<https://salsa.debian.org/games-team/openjk/commit/22fd18c4f2fb01bce65bc8737536c123c5f4bceb>

(But I still think we should make SDL2 stop breaking these games'
assumptions.)

    smcv