[Bug-glpk] GLPK Simplex behavior with meth=GLP_PRIMAL vs meth=GLP_DUALP

[IITK]

I have a linear program with no objective function. So I just want to test its feasibility. I am using GLPK api for simplex to do that. When I run simplex with the default method (meth=GLP_PRIMAL), the solver fails to converge in 100000 iterations (that is the limit I have set). However, when I use the method GLP_DUALP, after a few iterations I get the message "Warning: dual degeneracy; switching to primal simplex" and it does converge in a reasonable number of iterations.

So my question is if it ultimately uses the primal simplex in both cases, why does it not converge in the first case. What might be going on.

The same behavior is observed irrespective of whether the linear program has a primal feasible solution or not.

Thanks in advance.