BobcatParser model download fails due to unreachable qnlp.cambridgequantum.com (DNS resolution error)

[Yahya3mn]

When instantiating a BobcatParser object, lambeq attempts to retrieve the model version from:

https://qnlp.cambridgequantum.com/models/bobcat/latest/version.txt

However, the remote host cannot be resolved. The domain appears to be unavailable (DNS resolution fails), causing an immediate ModelDownloaderError.

The issue occurs before any local model caching logic can proceed.

Error Trace

ModelDownloaderError: ModelDownloader raised error: Failed to retrieve remote version number from https://qnlp.cambridgequantum.com/models/bobcat/latest/version.txt

Network test:

$ ping qnlp.cambridgequantum.com
ping: cannot resolve qnlp.cambridgequantum.com: Unknown host

DNS test:

$ nslookup qnlp.cambridgequantum.com
** server can't find qnlp.cambridgequantum.com: NXDOMAIN

Environment

lambeq version: 0.5.0

Python version: 3.11.14

OS: Ubuntu (Linux) 24 LTS

[bllin001]

Same error, I am trying to use either Bobcat or Oncilla, but it fail during execution. The script model_downloader.py uses the old link

[Yahya3mn]

Same error, I am trying to use either Bobcat or Oncilla, but it fail during execution. The script model_downloader.py uses the old link @bllin001

Hello, I solved the issue. If you’re wondering how, someone in the lambeq community Discord channel shared the Bobcat parser model files with us, and I tried them. It worked. You can reach via this link https://discord.com/channels/905463572497321995/905464006356140052