Do not use Homebrew dependencies.
--- src/CMakeLists.txt.orig	2019-11-21 12:30:13.000000000 -0600
+++ src/CMakeLists.txt	2019-11-23 14:26:54.000000000 -0600
@@ -30,10 +30,6 @@
   set(DEFAULT_DATADIR "Contents/Resources")
   set(DEFAULT_SAVEDIR ".")
   set(PLATFORM_PROVIDES_UGLY_CRASH true)
-
-  # this is so we can find Homebrew components
-  include_directories(SYSTEM /usr/local/include)
-  link_directories(/usr/local/lib)
 elseif (WINDOWS)
   set(SET_SDL_ICON TRUE)
   set(DEFAULT_DATADIR ".")
@@ -42,9 +38,6 @@
    set(SET_SDL_ICON TRUE)
    set(DEFAULT_DATADIR "${CMAKE_INSTALL_PREFIX}/share/raceintospace")
    set(DEFAULT_SAVEDIR ".")
-  # this is so we can find Homebrew components
-  include_directories(SYSTEM /usr/local/include)
-  link_directories(/usr/local/lib)
 endif ()
 
 # generate the raceintospace_config.h