Hunk#1: Don't run ccache unconditionally
Hunk#2: Don't build with -Werror

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -5,11 +5,6 @@ set(CMAKE_OSX_DEPLOYMENT_TARGET "10.9"
     CACHE STRING "Minimum macOS deployment version"
 )
 
-find_program(CCACHE_PROGRAM ccache)
-if(CCACHE_PROGRAM)
-    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
-endif()
-
 project(firewallbuilder LANGUAGES CXX C)
 
 ### Version variables and include file
@@ -45,7 +40,7 @@ endif()
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 set(CXX_DEFAULT_FLAGS # clang/GCC warnings
-	$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-Wall;-Wextra;-Werror;-Wno-overloaded-virtual>
+	$<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:-Wall;-Wextra;-Wno-overloaded-virtual>
                          # MSVC warnings
     $<$<CXX_COMPILER_ID:MSVC>:/WX;/W4>)