The answers already provided do include all the necessary steps, just not in a single answer, so here goes (assumes you have already installed Git, which seems to be the case based on your question):
git clone https://github.com/vrai/fdspatch
This will report the warning about
tempnam that you are already aware of, as stated elsewhere, this is a warning, not an error; the program will still run.
Let's prove the binary you have just built works, from the same
fdspatch directory run:
As we didn't provide any of the expected parameters, this will show the help file of the tool. If you're happy only being able to run this command from the
fdspatch directory, there's no further action needed.
If you want to be able to run the
fdspatch command from anywhere, you'll need to copy it to the systems binary directory (this IS documented on the project's github page, but the details are left to the reader...)
Assuming you're on the latest Raspberry Pi OS, this should work (again, assumes you are still in the fdspatch directory):
sudo cp fdspatch /usr/local/bin
You can then run the
fdspatch command anywhere on the system.
All of the above has been tested and and shown to work on a RPi4 on latest Raspberryb Pi OS.