use distutils.spawn.find_executable

install

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 from __future__ import division, with_statement, print_function
 
+import distutils.spawn
 from contextlib import closing
 import json
 import os
@@ -8,7 +9,6 @@ import sys
 import tarfile
 from urllib.request import urlopen
 from threading import Thread
-import subprocess
 
 def makedirs(dirname):
     if not os.path.exists(dirname):
@@ -163,7 +163,8 @@ class Install(Thread):
         return self.base_url + url
 
 def has_bin(cmd):
-    return subprocess.call(['which', cmd], stdout=subprocess.PIPE) == 0
+    path = distutils.spawn.find_executable(cmd)
+    return path != None
 
 if __name__ == '__main__':
     if len(sys.argv) == 1: