generic linux architecture subclass

lib/spack/spack/architectures/linux.py

@@ -0,0 +1,17 @@
+import subprocess 
+from spack.architecture import Architecture
+
+class Linux(Architecture):
+    priority    = 60 
+    front_end   = "x86_64"
+    back_end    = "x86_64"
+    default     = "x86_64"
+
+    def __init__(self):
+        super(Linux, self).__init__('linux')
+
+    @classmethod
+    def detect(self):
+        arch = subprocess.Popen(['uname', '-i'], stdout = subprocess.PIPE)
+        arch, _ = arch.communicate()
+        return 'x86_64' in arch.strip()