L1/2 regularized logistic regression

Your output does not show a claim that the (failed) problem is infeasible. The output shoiws a failure of CVX’s successive approximation method, which can fail even for problems which are well formulated and have (finite) optimal solutions.

Use CVXQUAD

and show us the results. I do not guarantee the problem will be solved using CVXQUAD, but it might. In order to maximize your chances of success, if you have CVX professkional or academic versions, and have Gurobi or Mosek solvers available, specify one of them as cvx_solver, because they are better solvers than SeDuMi and SDPT3.