Nimbus v22.12.0 doesn't recognize --log-level={trace,debug,info,notice,warn,error,fatal}

[tersec]

There's a backwards-incompatible regression in --log-level parsing.

Nimbus v22.11.1 recognized all of these:

$ build/nimbus_beacon_node --version
Nimbus beacon node v22.11.1-e4b193-stateofus
Copyright (c) 2019-2023 Status Research & Development GmbH

eth2 specification v1.3.0-alpha.1

Nim Compiler Version 1.2.16 [Linux: amd64]
$ build/nimbus_beacon_node --log-level=trace
... runs ...
$ build/nimbus_beacon_node --log-level=debug
... runs ...
$ build/nimbus_beacon_node --log-level=info
... runs ...
$ build/nimbus_beacon_node --log-level=warn
... runs ...
$ build/nimbus_beacon_node --log-level=notice
... runs ...
$ build/nimbus_beacon_node --log-level=error
... runs ...
$ build/nimbus_beacon_node --log-level=fatal
... runs ...

And with v22.12.0:

$ build/nimbus_beacon_node --version
Nimbus beacon node v22.12.0-f6a5a5-stateofus
Copyright (c) 2019-2023 Status Research & Development GmbH

eth2 specification v1.3.0-alpha.2

Nim Compiler Version 1.6.11 [Linux: amd64]
$ build/nimbus_beacon_node --log-level=info
Invalid value for --log-level. Please specify one of TRACE, DEBUG, INFO, NOTICE, WARN, ERROR or FATAL

and the others show the same error message, then immediately quit.

[zah]

Probably caused by the upgrade to Nim 1.6

[tersec]

Built v22.12.0 with Nim 1.2 and can confirm that it seems to fix this.

Why would Nim 1.6 have affected this?