Daily Sudoku of Donaukurier cracked

I'm currently fiddling around with a Sudoku puzzle solver implemented in Rust language.
At the moment it needs some more optimizing in handling very difficult grid templates with an acceptable memory footprint.

But it is fast enough for the daily Sudoku puzzle in our newspaper Donaukurier.

After the code profiling and optimizing the idea is to implement a(nother) WebService to solve Sudokus. ;-)