How to use the u-root version of "scp" #2862

Im trying to use and understand how the u-root implementation of scp works. Reading the code shows that it expects a response and sends a reply, then transfers the file using io.Copy()... But when I try to use this tool it just hangs indefinitely

this is my assumption of how this is supposed to be used:

./scp -f ./my_file | ssh remote_host './scp -t ./my_file2'
# but it does nothing but hang forever

I've done a lot of other tests but I cannot sus out how this is supposed to work. even something like "./scp -f file | ./scp -t file2" hangs forever. Im really not sure how these two things are supposed to communicate.