One thing that occurred to after reporting was whether revision of wxWidgets would affect header usage. I have 3.0.5 installed.
The fix changing a forward declaration to a header include works for me on a Linux. Build completes with error.
Platform x86_64 Gentoo using kernel 5.15.41 GCC 11.2.1 (patch 20220115 gentoo p4) Building trunk at this revision produced the following error message in build log: x86_64-pc-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I../../src/include -I/usr/lib64/wx/include/gtk3-unicode-3.0-gtk3 -I/usr/include/wx-3.0-gtk3 -D_FILE_OFFSET_BITS=64 -DWXUSINGDLL -D__WXGTK__ -pthread -I../../src/include/scripting/include -I../../src/sdk/wxscintilla/include -I../../src/include -DENABLE_BINRELOC -DAPP_PREFIX="\"/usr\"" -I/usr/include/gtk-3.0...
Add mission_description field on quests.lua
Ground Level Map Connections Update.