Second attempt to fix build on Alpine Linux. issues 150, 319, 344.

external/misc/CMakeLists.txt

@@ -32,9 +32,22 @@ if(LINUX)
       )
   endif()
 
+  # Add_library doesn't like to get an empty source file list.
+  # I tried several variations on this theme to test whether the list
+  # was not empty and was not successful in getting it to work
+  # on both Alpine and RPi.
+  #if("${misc_SOURCES}")
+  # This is less elegant and less maintainable but it works.
+
+  if ((NOT HAVE_STRLCPY) OR (NOT HAVE_STRLCAT))
     add_library(misc STATIC
       ${misc_SOURCES}
       )
+  else()
+    set(MISC_LIBRARIES "" CACHE INTERNAL "")
+  endif()
+
+
 
 elseif(WIN32 OR CYGWIN) # windows