Heh, I actually just ran into transaction pinning in real life: so LND v0.18 has a new sweeper scheme, that, long story short, is trying to "sweep" both nearly worthless anchor outputs, and valuable outputs, from some LN channels I closed in the same transaction.

The anchor outputs are past their 16 block timeout, so someone else is trying to sweep them in a huge 3sat/vB transaction paying ~60,000 in fees. Far more than I can afford! But still a low fee-rate.

On my replace-by-fee-rate nodes the sweep will eventually succeed once LND picks a high enough fee rate (it repeatedly RBFs the sweeps). It might even get mined, either on a pool like F2Pool with short mempool expiration, or in the near future when turns on RBFR like they told me they would Soon™.