Thanks. I also added your patch to MXE Octave until there is a release with this fixed:
https://hg.octave.org/mxe-octave/rev/8fcac4d6d983

With Octave 7.1.0 and queueing 1.2.7:

octave:1> pkg load queueing
octave:2> test qnmknode
***** test
 fail( "qnmknode( 'pippo', 1 )", "must be one" );
 fail( "qnmknode( '-/g/1-ps', 1, 1, 1)", "Invalid call" );
!!!!! test failed
expected error <Invalid call>
but got <print_usage: function called with too many outputs>

The problem comes from the fact that print_usage() is called within a logical expression. Since print_usage() does not return a value, this fails with Octave 7 since the latter does stricter checks on number of output arguments.