mithril.js: NotSupportedError: DOM Exception 9: The implementation did not support the requested type of object or operation.

As of 270b20a2b029da7a5807648f43e31798eb7e0e96, I’m getting this error in Safari (9.0.1). Chrome is unaffected.

NotSupportedError: DOM Exception 9: The implementation did not support the requested type of object or operation.

The stack trace points to createContextualFragment on this line. Looking back at the previous commit, it looks like this part was refactored and a surrounding try/catch was removed?