attempt to add a flag to disable backtrace (#120)

CMakeLists.txt

@@ -40,6 +40,7 @@ option(CROSS_COMPILE_AARCH64 "Cross-compile for 64-bit ARM" off)
 option(COMPILE_WIN32 "Compile for Win32" off)
 
 set(ENABLE_LIBDW_SUPPORT ON)
+option(ENABLE_BACKWARD "Enable support for backtraces" ON)
 
 if (COMPILE_WIN32)
     set(ARCH amd64)
@@ -193,6 +194,7 @@ if (NOT DISABLE_WEBSOCKETS)
 endif (NOT DISABLE_WEBSOCKETS)
 
 # elfutils (libdw-dev)
+if (ENABLE_BACKWARD)
     if (ENABLE_LIBDW_SUPPORT)
         find_path(LIBDW_INCLUDE_DIR NAMES elfutils/libdw.h elfutils/libdwfl.h HINTS /usr /usr/local PATH_SUFFIXES include)
 
@@ -217,6 +219,10 @@ else()
         set(LIBDW_INCLUDE_DIR "")
         set(LIBDW_LIBRARY "")
     endif (ENABLE_LIBDW_SUPPORT)
+else()
+    message("-- backtrace has been disabled per user request. Here be dragons!")
+    add_definitions(-DBACKWARD_HAS_BACKTRACE_SYMBOL=0 -DBACKWARD_SYSTEM_UNKNOWN=1)
+endif (ENABLE_BACKWARD)
 
 # FinalCut
 if (ENABLE_TUI_SUPPORT AND NOT FC_INCLUDED)