message: Simplify uname command
diff: export builddir=$(abspath ./build)
  export prefix=$(abspath ./install)
  CXX=g++
  -uname_os := $(shell sh -c 'uname -s 2>/dev/null || echo not')
  +uname_os := $(shell uname)
  ARCH := $(shell getconf LONG_BIT)
  SHARED_LIB_EXT:=.so
  INCLUDE_ARCHIVES_START = -Wl,-whole-archive # linking options, we prefer our generated shared object will be self-contained.
  