Synopsys Sentaurus DNS issue
Synopsys Sentaurus is an industry-standard TCAD (Technology Computer-Aided Design) software suite for simulation of semiconductors (fabrication, physical behavior, electrical characteristics etc.) We found a problem when installing it on some of our Linux systems (Rocky 8.10). We could start up the swb application ok and choose a project to run (e.g. an example like swb/mosfet - copy this to a writable location). Once the project was loaded the interface got very laggy, and running the project resulted in not much happening. You can see this by opening the project log (there’s a menu item for this) - it gets to INFO: Starting new project execution... and then nothing happens.
In this case you want to abort the project before you try to run it again, otherwise it complains it’s locked or read-only.
You can look at the daemon process logs to see what is going on. These are located in ~/.swb/swblm/Y-2026.03/ (or whatever version of sentarus you are running). For the problematic systems swblm.err had the error:
ERROR: getaddrinfo(): error getting host by name
This looks like a DNS error - it can’t get the host IP address. The networking setup of a working and non-working system were almost identical - one difference noted was /etc/resolv.conf. Oddly, getent NAMEOFHOST worked, which should go through the standard glibc getaddrinfo() function. Also trying it in python (run python or python3 then):
import socket
socket.getaddrinfo('NAMEOFHOST', 22)
gives an answer where the IP address is shown. It could be that swblm uses a abked-in version that has a bug or non-standard behavior?
The fix was to add the IP address of the system to /etc/hosts, i.e.
IP_ADDRESS HOSTNAME HOSTNAME.FQDN
Once this was done, the swb interface was no longer laggy when a project was loaded, and running the project worked (logs showed stuff was happening).
I’m still not sure why the particular combination of DNS servers seems to be the problem, but at least the immediate issue was fixed.