[Emacspeak] Compiling emacspeak on Nix OS

[Harley Richardson <destructatron2018@xxxxxxxxx>]

Hello,

I've been trying to get the latest emacspeak to work on nix OS, as 56.0 
has some issues, mainly to do with sounds not playing and shortcuts I'm 
used to not being there. Everything is fine until it tries to compile 
the espeak server. I end up getting the following error:

tclespeak.cpp:41:10: fatal error: espeak-ng/speak_lib.h: No such file or 
directory
   41 | #include <espeak-ng/speak_lib.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [<builtin>: tclespeak.o] Error 1
Can't build espeak server!

This was after I ran make espeak in the emacspeak directory. I tried 
installing espeak-ng both in regular and environment packages, that 
didn't fix it. Am I doing something wrong, or is this just me being new 
to nix?

Harley