How to solve cannot dissect LTE-RLC frame because no per frame info was attached error in wireshark.

You cannot call directly the RLC LTE dissector as it requires some metadata (RLC mode, Sequence Number length, ...) that are normally provided by the Catapult product, or by the UDP framing protocol described here.

So you need to modify the openlte code to match this UDP framing protocol (that adds the per frame info), and then enable the "try heuristic LTE-RLC over UDP framing" option in Wireshark.

Alternatively, you can follow this link, you can find the start of a development adding support for the dump of LTE MAC PDUs (by addeing the per frame info required by the dissector) coming from openlte. But the contributor did not do any follow-up after the initial review so it has stalled.

Anyway, this is more an openlte question than a Wireshark one. It's up to them to decide which format (UDP framing or enhancement of the GSMTAP format) they want to use. If this is the latter, then they should do a follow-up of the Gerrit code review above. I'm willing to help them but it seems like they lost interest.