A lot of segfaults explained

[armleo]

I don't know where to document this. So doing it here. If somebody can suggest better place, do so, I will put it there.

If fastroute/cugr crashes with segfault, most likely reason is:

1. You have power net, that is not under PG_DEFINE. This causes router to try to route the VPWR/VGND and it segfaults without any error, right after read_sdc
2. If you have a pin outside of die area, it outputs an warning and then later crashes with segfault and no error message

Detailed router crashes:
[ERROR DRT-0074] No ap for PIN/fastio_in[16].

AP stands for access point. Unfortunetly can't resolve it, but I suspect, it is caused by the pin being missaligned on the grid/being too small.

[mithro]

@armleo - Just FYI -- The OpenLane / OpenROAD tooling should never segfault not matter how bad the input is.

[mithro]

At the moment I don't believe you have provided enough information to reproduce the segfault so that it can be fixed?

[armleo]

will create an issue, as soon as I can reproduce it properly, without using my verilog/def. Maybe will make a simple design for this. Keep in mind, this is for openlane installed by caravel mpw5a

[mithro]

FYI - @donn / @maliberty

[maliberty]

I know the cause of "[ERROR DRT-0074] No ap for PIN/fastio_in[16]." leading to a crash and fixed it this morning in The-OpenROAD-Project/OpenROAD#1627

You will get an error without an abort now.

[armleo]

Is there any chance to get this backported to mpw5a?

[armleo]

Created #909

[armleo]

Created #912 for ap issue.

[armleo]

[maliberty]

This seems unrelated to the original request. If so it should be a separate discussion.

[donn]

Matt is right.