HACKY WORKAROUND: Don't use std::filesystem on mingw because the version in Debian Buster has a bug.

Author: rpavlik

src/CMakeLists.txt

@@ -24,6 +24,9 @@ set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 option(BUILD_LOADER "Build loader" ON)
 option(BUILD_ALL_EXTENSIONS "Build loader and layers with all extensions" OFF)
 option(BUILD_LOADER_WITH_EXCEPTION_HANDLING "Enable exception handling in the loader. Leave this on unless your standard library is built to not throw." ON)
+if(MINGW)
+    option(BUILD_WITHOUT_STD_FILESYSTEM "Build without std::[experimental::]filesystem, to work around standard library bugs" ON)
+endif()
 if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
     option(DYNAMIC_LOADER "Build the loader as a .dll library" OFF)
 else()

src/loader/CMakeLists.txt

@@ -207,6 +207,11 @@ if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
         PRIVATE -fno-strict-aliasing -fno-builtin-memcmp "$<$<COMPILE_LANGUAGE:CXX>:-fno-rtti>"
         -ffunction-sections -fdata-sections
     )
+    if(BUILD_WITHOUT_STD_FILESYSTEM)
+        target_compile_definitions(openxr_loader PRIVATE DISABLE_STD_FILESYSTEM)
+    else()
+        target_link_libraries(openxr_loader PRIVATE stdc++fs)
+    endif()
     # For GCC version 7.1 or greater, we need to disable the implicit fallthrough warning since
     # there's no consistent way to satisfy all compilers until they all accept the C++17 standard
     if (CMAKE_COMPILER_IS_GNUCC AND NOT (CMAKE_CXX_COMPILER_VERSION LESS 7.1))