upgradewallet on a descriptor wallet ends with error

[jsarenik]

This is the error I get:

$ bitcoin-cli -rpcwallet=descriptor -testnet upgradewallet                         <
error code: -1
error message:
wallet/rpcwallet.cpp:4522 (operator())
Internal bug detected: '!error.empty()'
You may report this issue here: https://github.com/bitcoin/bitcoin/issues

The daemon logs this:

2021-07-15T16:16:54Z [descriptor] Performing wallet upgrade to 169900

Expected behavior

When I do the same on the default (non-descriptor) wallet:

$ bitcoin-cli -rpcwallet="" -testnet upgradewallet                             
{
  "wallet_name": "",
  "previous_version": 169900,
  "current_version": 169900,
  "result": "Already at latest version. Wallet version unchanged."
}

System information

Bitcoin Core v0.21.1 Linux x86_64 glibc (Ubuntu) using binarias from bitcoincore.org