# report_worst_slack returns INF

Tool: OpenSTA

Subcategory: Timing analysis issue

## Conversation

### xiaosinju
I have run the following script:
```
read_lef ispd19_test6.input.lef
read_def ispd19_test6.input.def
set thread_count 8
global_route
detailed_route
write_db route.db
report wns
>> wns 0
report tns
>> tns 0
report worst_slack
>> worst slack INF
```
Did anything go wrong? How can I get correct metrics? Thanks a lot!

### vijayank88
Do estimate parasitic and then report the metrics. Refer here: https://github.com/The-OpenROAD-Project/OpenROAD/blob/master/test/flow.tcl#L264-L280 @xiaosinju 

### maliberty
This is a routing test case and has no timing information (no .lib or .sdc).  What are you trying to accomplish?