Unrecognized service: `10.16.176.5:40077*'. Trying again in 1.00 seconds...
Unrecognized service: `10.16.176.5:40077*'. Trying again in 1.20 seconds...
Unrecognized service: `10.16.176.5:40077*'. Trying again in 1.44 seconds...
Unrecognized service: `10.16.176.5:40077*'. Trying again in 1.73 seconds...
The output is from a long running script which is altering wireguard configuration and sometimes doing a wget. I can not preproduce, but have seen it happen at least twice. 10.16.176.5:40077 is an endpoint I am trying to connect with.
ldd is the only program which has "Unrecognized service", but it does not also contain the string "Trying again in"
root@o34# grep -l Unrecognized /usr/bin/*
root@o34# strings /usr/bin/ldd | grep Unrecognized
Unrecognized address family or invalid length
Unrecognized socket type
This error message corresponds to the EAI_SERVICE error code of the libc getaddrinfo() call, means the given service parameter to the call (either a symbolic name like http as defined in /etc/services or a string containing a decimal port number) was invalid or not applicable to the used address family.
From the messages above it looks as if something failed to split/parse the address:port tuple properly before passing it to getaddrinfo(), leading to the message above.
Unfortunately, getaddrinfo() is a low level libc call and there's numerous executables that might invoke it directly or indirectly.
The retry behavior quoted above does not sound familiar for any busybox applet or OpenWrt specific utility though, so it likely comes from an optional program invoked by your script.