Make unzip quiet (#2593)

lib/spack/spack/cmd/create.py

@@ -314,7 +314,7 @@ def __call__(self, stage, url):
         if stage.archive_file.endswith('.zip'):
             try:
                 unzip  = which('unzip')
-                output = unzip('-l', stage.archive_file, output=str)
+                output = unzip('-lq', stage.archive_file, output=str)
             except:
                 output = ''
         else:

lib/spack/spack/util/compression.py

@@ -45,6 +45,7 @@ def decompressor_for(path, extension=None):
     if ((extension and re.match(r'\.?zip$', extension)) or
             path.endswith('.zip')):
         unzip = which('unzip', required=True)
+        unzip.add_default_arg('-q')
         return unzip
     if extension and re.match(r'gz', extension):
         gunzip = which('gunzip', required=True)