Followup for bug 1421100: deterministically download rustc 1.23.0-beta.2. r=me, a=bustage on a CLOSED TREE

taskcluster/ci/toolchain/windows.yml

@@ -158,7 +158,7 @@ win32-rust-1.23.0-beta.2:
         using: toolchain-script
         script: repack_rust.py
         arguments: [
-            '--channel', 'beta',
+            '--channel', 'beta-2017-12-08',
             '--host', 'i686-pc-windows-msvc',
             '--target', 'i686-pc-windows-msvc',
         ]

taskcluster/scripts/misc/repack_rust.py

@@ -242,7 +242,13 @@ def tar_for_host(host):
 
 
 def fetch_manifest(channel='stable'):
-    url = 'https://static.rust-lang.org/dist/channel-rust-' + channel + '.toml'
+    if '-' in channel:
+        channel, date = channel.split('-', 1)
+        prefix = '/' + date
+    else:
+        prefix = ''
+    url = 'https://static.rust-lang.org/dist%s/channel-rust-%s.toml' % (
+        prefix, channel)
     req = requests.get(url)
     req.raise_for_status()
     manifest = toml.loads(req.content)