Runtime error after executing a command: `Fatal error: exception Unix.Unix_error(Unix.EINTR, "waitpid", "")`

[barracuda156]

With a few hacks I got it building, but it does not work correctly:

Welcome, 
Gufo is an Unidentified Flying Object but it also means 'Owl' in esperanto. 

This program is GPLV3, created by Pierre Vittet. 
This is a pre-release experimental version.

To escape GUFO, just press escape.
Term size: rows:24 col:80
----------------------------------
% sw_vers
ProductName:	Mac OS X
ProductVersion:	10.15.7
BuildVersion:	19H2026
Fatal error: exception Unix.Unix_error(Unix.EINTR, "waitpid", "")

[Process completed]

Welcome, 
Gufo is an Unidentified Flying Object but it also means 'Owl' in esperanto. 

This program is GPLV3, created by Pierre Vittet. 
This is a pre-release experimental version.

To escape GUFO, just press escape.
Term size: rows:24 col:80
----------------------------------
% pwd
/Users/svacchanda
Fatal error: exception Unix.Unix_error(Unix.EINTR, "waitpid", "")