Again, Cygwin supports SYSV IPC. Please inform the original author that
the functionality depends on a running cygserver process. If this
process is not running, the SYSV IPC functions return ENOSYS.
IMHO there's no reason to exit if the msgget function returns ENOSYS.
The code could simply note the fact and proceed, and only return an
error if the user tried the -R option.
SYSV message queue support in Cygwin exists, but it requires to run
cygserver. If you want to avoid this dependency, you can use POSIX
message queues instead.