Seeing as you merged rr1-maint into master, I did some git pull'ing and ran into lua issues on the master branch, namely lua_callback_do_unsafe_rewind being undefined when linking. It seems you have neglected to update the signature in lua's dummy.cpp. This simple patch fixes it:
diff --git a/src/lua/dummy.cpp b/src/lua/dummy.cpp
index 38bd91b..d212782 100644
--- a/src/lua/dummy.cpp
+++ b/src/lua/dummy.cpp
@@ -27,7 +27,7 @@ void lua_callback_keyhook(const std::string& key, const struct keygroup::paramet
void init_lua() throw() {}
void quit_lua() throw() {}
uint64_t lua_timed_hook(int timer) throw() { return 0x7EFFFFFFFFFFFFFFULL; }
-void lua_callback_do_unsafe_rewind(const std::vector<char>& save, movie& mov, void* u) {}
+void lua_callback_do_unsafe_rewind(const std::vector<char>& save, uint64_t secs, uint64_t ssecs, movie& mov, void* u) {}
bool lua_requests_repaint = false;
About the GB namespace before: Somehow the forums don't like stuff in angle brackets. It was supposed to #include [gameboy/gameboy.hpp].