Add an extremely horrible hack to allow the python bindings to build

on gcc11

Don't blame me, blame sip

python/CMakeLists.txt

@@ -162,6 +162,12 @@ GENERATE_SIP_PYTHON_MODULE_CODE(qgis._core core/core.sip "${sip_files_core}" cpp
 BUILD_SIP_PYTHON_MODULE(qgis._core core/core.sip ${cpp_files} "" qgis_core)
 set(SIP_CORE_CPP_FILES ${cpp_files})
 
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  # Bad hack to fix compilation with gcc 11 - for some reason it's ignoring
+  # the c++ standard version set for the target in BUILD_SIP_PYTHON_MODULE!
+  add_definitions(-std=c++14)
+endif()
+
 if(UNIX AND NOT SIP_VERSION_NUM LESS 265984)
   set(SIP_EXTRA_OPTIONS -P ${SIP_EXTRA_OPTIONS})
   add_definitions(-Dprotected=public)