You can see on the release page if it's an uploaded tarball or a git tag:
-- If there is a green download button, like
- https://github.com/zedshaw/mongrel2/releases/tag/v1.9.1[mongrel2], then it
- was uploaded by the maintainer and you should use the link of that button to
- specify +FOO_SITE+, and not use the 'github' helper.
-- If there is grey download button, like
- https://github.com/xbmc/xbmc/releases/tag/13.2-Gotham[xbmc], then it's an
- automatically generated tarball and you should use the 'github' helper
- function.
+image::github_hash_mongrel2.png[]
+
+- If it looks like the image above then it was uploaded by the
+ maintainer and you should use that link (in that example:
+ 'mongrel2-v1.9.2.tar.bz2') to specify +FOO_SITE+, and not use the
+ 'github' helper.
+
+- On the other hand, if there's is *only* the "Source code" link, then
+ it's an automatically generated tarball and you should use the
+ 'github' helper function.