Comparing with your previous ldd --verbose ./main, the main difference is the following:
- /nix/store/35pq4hr29c3sl79lgfwgsvd9nwzyp4am-glibc-2.39-5/lib/ld-linux-x86-64.so.2 => /nix/store/apab5i73dqa09wx0q27b6fbhd1r18ihl-glibc-2.39-31/lib64/ld-linux-x86-64.so.2 (0x00007f598a5af000)
+ /nix/store/apab5i73dqa09wx0q27b6fbhd1r18ihl-glibc-2.39-31/lib/ld-linux-x86-64.so.2 => /nix/store/apab5i73dqa09wx0q27b6fbhd1r18ihl-glibc-2.39-31/lib64/ld-linux-x86-64.so.2 (0x00007f37efd52000)
You have glibc-2.39-5 pointing to glibc-2.39-31. Would this probably be the cause of the issue?
Edit:
$ LD_PRELOAD="/nix/store/35pq4hr29c3sl79lgfwgsvd9nwzyp4am-glibc-2.39-5/lib/ld-linux-x86-64.so.2" ./whispers
Floating point exception (core dumped)
$ LD_PRELOAD="/nix/store/apab5i73dqa09wx0q27b6fbhd1r18ihl-glibc-2.39-31/lib/ld-linux-x86-64.so.2" ./whispers
whispering on http://localhost:8080/
This might be related to this:
In effect, one of the packages in your home.nix/dev.nix might be interfering with go.
If you try this, does it work?
$ nix-shell --pure -p go
$ go run ./main.go