find_latest.py: Report no latest build found more appropriately.

Previously, there was low-level exception on list.pop().

1 files changed, 2 insertions, 0 deletions

diff --git a/find_latest.py b/find_latest.py
index 7441a4e..1b7cb26 100755
--- a/find_latest.py
+++ b/find_latest.py
@@ -69,6 +69,8 @@ def find_latest(url):
     dates = find_builds(builddates)
     dates = [int(date) for date in dates]
     dates.sort()
+    if not dates:
+        raise ValueError("No builds found at index url: " + url)
     lastdate = dates.pop()
     lastdate = str(lastdate) + "/"
     latesturl = urlparse.urljoin(url, lastdate)