ERR: On systems where uname does not support -p, try -m. Fixes Bug #426 - CMAKE_SYSTEM_PROCESSOR unknown and inconsistent

Modules/CMakeDetermineSystem.cmake

@@ -31,6 +31,12 @@ IF(UNIX)
     EXEC_PROGRAM(uname ARGS -s OUTPUT_VARIABLE CMAKE_SYSTEM_NAME)
     EXEC_PROGRAM(uname ARGS -r OUTPUT_VARIABLE CMAKE_SYSTEM_VERSION)
     EXEC_PROGRAM(uname ARGS -p OUTPUT_VARIABLE CMAKE_SYSTEM_PROCESSOR)
+    IF(${CMAKE_SYSTEM_PROCESSOR} MATCHES "--help")
+      EXEC_PROGRAM(uname ARGS -m OUTPUT_VARIABLE CMAKE_SYSTEM_PROCESSOR)
+    ENDIF(${CMAKE_SYSTEM_PROCESSOR} MATCHES "--help")
+    IF(${CMAKE_SYSTEM_PROCESSOR} MATCHES "--help")
+      SET(CMAKE_SYSTEM_PROCESSOR "unknown")
+    ENDIF(${CMAKE_SYSTEM_PROCESSOR} MATCHES "--help")
     SET(CMAKE_UNAME ${CMAKE_UNAME} CACHE INTERNAL "uname command")
   ENDIF(CMAKE_UNAME)
 ELSE(UNIX)