nom hanging?

[winterqt]

I have a script that calls nom-build. In rare, unexplainable cases, nom-build freezes at just the timer, with no output, for minutes on end. If I switch the script to calling nix-build instead, everything functions as normal.

How exactly would I begin to debug this? It’s not easily reproducible, but I’d be happy to try and do so.

[maralorn]

Does the timer stop at some second? Is there a pattern in which one? Or does it just remain at the timer?

[winterqt]

Or does it just remain at the timer?

This, unfortunately — it goes on for as long as you let it as far as I can tell.

[maralorn]

Is there significant CPU/memory usage by nom while this is happening?
There is also no log being printed, right?

[winterqt]

No to both.

[maralorn]

I might actually also have witnessed something like that in rare cases. As it seems nearly like nom is not receiving any input at all I wonder if there is some kind of input which can send the parser into an invalid state after which it will not parse anything successfully.