Fix snapshot downloading on Python 3

This regression, introduced in d3f590f59ff72f1d3b457ed3716483ce472053c6
in #1674, caused `make` to fail on machines where `python` is Python 3
rather than Python 2, because `dict.keys()` returns a set-like object
that does not support indexing rather than a list.

`date = next(iter(snaps.keys()))` would be an adequate fix too, but I’m
not particularly happy with either of them, for neither would stand up
to the removal of the `break` statement: one is inadequate because
dictionaries are unordered collections, the other is inadequate because
`current` would refer to the *last* rather than the *first* snapshot in
the file.

diff --git a/src/etc/dl-snapshot.py b/src/etc/dl-snapshot.py
index 4399229b8f177044226a42d40a02313b2270aa6a..97e394fa37387eaf28a9a3ec56f75b2914a3f60f 100644 (file)
--- a/src/etc/dl-snapshot.py
+++ b/src/etc/dl-snapshot.py
@@ -31,7 +31,7 @@ with open('src/snapshots.txt') as f:
         # no need to look past the first section.
         break
 
-date = snaps.keys()[0]
+date = current
 triple = sys.argv[1]
 
 ts = triple.split('-')