synch achieved:

There are currently 2 issues:

- fetch genesis state on empty data folder:
error msg "The downloaded genesis state cannot be verified (checksum mismatch)\"

The error arises from here:
   fetchGenesisState->network_metadata_downloads.fetchGenesisBytes.L58
something to do with the readssz or withState, investigations point to the data downloaded or some config missing
WA: comment lines 58-62, compile and run until the fetch genesis state is completed, then you can uncomment, it works from here

- spam of error messages: \"metrics error:New label values must be added from same thread as the metric was created from\":
This happens due to the fact that libp2p declares some gauges, and given that they are created inside a thread, metrics library
starts to complain. (no WA/correction so far)"

Makefile

@@ -370,9 +370,10 @@ endif
 # Nimbus unified related targets
 
 # builds the unified client
+# NIM_PARAMS := -d:release --parallelBuild:1 -d:libp2p_agents_metrics -d:KnownLibP2PAgents=nimbus,lighthouse,lodestar,prysm,teku,grandine $(NIM_PARAMS)
 nimbus_unified: | build deps
 	echo -e $(BUILD_MSG) "build/$@" && \
-		$(ENV_SCRIPT) nim c $(NIM_PARAMS)  --verbosity:3 -d:debug -d:disable_libbacktrace -d:libp2p_pki_schemes=secp256k1 -d:chronicles_log_level=TRACE -o:build/$@ "nimbus_unified/$@.nim"
+		$(ENV_SCRIPT) nim c $(NIM_PARAMS) -d:disable_libbacktrace -d:libp2p_pki_schemes=secp256k1 -o:build/$@ "nimbus_unified/$@.nim"
 # Note about building Nimbus as a library:
 #
 # There were `wrappers`, `wrappers-static`, `libnimbus.so` and `libnimbus.a`