# Using deltaDebug.py to whittle down detailed routing example

Tool: Detailed Routing

Subcategory: Detailed routing issue

## Conversation

### oharboe
I have some violations that detailed routing isn't able to deal with, that I really think it should be able to deal with.

Normally, deltaDebug.py needs an error message to look for to do it's bisection.

However, a detailed route can succeed after 64 iterations, even if all violations are not sorted out, so there's no error message for  deltaDebug.py to use for it's bisection.

Tips?

### maliberty
Can you use --use_stdout & --error_string to check the final drcs?

### maliberty
You could make a temporary change to scripts/detail_route.tcl to call detailed_route_num_drvs and issue an error message if >0.  Then you could delta on that.

### oharboe
Various bugs have been fixed and improvements made to deltaDebug.py since this post.