Go back to using curl to download snapshots

configure

@@ -264,6 +264,7 @@ need_cmd sed
 need_cmd file
 need_cmd cmake
 need_cmd pkg-config
+need_cmd curl
 
 CFG_SRC_DIR="$(cd $(dirname $0) && pwd)/"
 CFG_BUILD_DIR="$(pwd)/"

src/etc/dl-snapshot.py

@@ -1,18 +1,11 @@
 import distutils.spawn
 import hashlib
 import os
+import subprocess
 import sys
 import tarfile
 import shutil
 
-try:
-    from urllib.request import urlopen
-except ImportError:
-    # We are in python2
-    from urllib2 import urlopen as urlopen2
-    from contextlib import closing
-    urlopen = lambda url: closing(urlopen2(url))
-
 with open('src/snapshots.txt') as f:
     lines = f.readlines()
 
@@ -77,13 +70,12 @@
 if os.path.isdir(dst):
     shutil.rmtree(dst)
 
-with urlopen(url) as in_file:
-    data = in_file.read()
-    h = hashlib.sha1(data).hexdigest()
-    if h != hash:
-        raise Exception("failed to verify the checksum of the snapshot")
-    with open(dl_path, 'wb') as out_file:
-        out_file.write(data)
+ret = subprocess.call(["curl", "-o", dl_path, url])
+if ret != 0:
+    raise Exception("failed to fetch url")
+h = hashlib.sha1(open(dl_path, 'rb').read()).hexdigest()
+if h != hash:
+    raise Exception("failed to verify the checksum of the snapshot")
 
 with tarfile.open(dl_path) as tar:
     for p in tar.getnames():