I needed the newgrf_gui and your pack is the only one working with it currently.
I had the fallowing warnings on compiling:
/home/marcel/bin/ottd/roest/src/group_gui.cpp: In function ‘void GroupWndProc(Window*, WindowEvent*)’:
/home/marcel/bin/ottd/roest/src/group_gui.cpp:500: warning: enumeral and non-enumeral type in conditional expression
/home/marcel/bin/ottd/roest/src/group_gui.cpp:504: warning: enumeral and non-enumeral type in conditional expression
/home/marcel/bin/ottd/roest/src/rule.cpp: In member function ‘Criteria* Rule::GetCriteriaAtPos(byte) const’:
/home/marcel/bin/ottd/roest/src/rule.cpp:127: warning: comparison is always false due to limited range of data type
/home/marcel/bin/ottd/roest/src/station_cmd.cpp: In function ‘CommandCost CmdBuildAirport(TileIndex, uint32, uint32, uint32)’:
/home/marcel/bin/ottd/roest/src/station_cmd.cpp

warning: unused variable ‘distant_join’
Greets
Ammler