This behaviour was introduced in v1.1 to make Sinatra play nice with Rails3.
Blank routes are punted to the '/' route, and so remain unreachable:
get '' do
This causes problems when trying to link to static assets relative to the root path. Examples can be seen in these two gists.
The workaround is to check if request.path_info.empty?, which is not pretty.
handle empty route patterns as expected without breaking rails 3 compatibility, closed by f438be2