Slow test generation for matrix with constraints

[tochilinak]

Description

UTBot Java cannot generate for a test that expects specific matrix as input in 3 minutes. However, it was able to do that in 5 minutes.

To Reproduce

Steps to reproduce the behavior:

1. Create project in IntelliJ Idea with the following code:

public class Main {
    int[][] func(int[][] x, int target) {
        int n = x.length;
        assert (n >= 5);
        for (int[] ints : x) {
            assert (ints.length == n);
            for (int j = 0; j < n; j++) {
                assert (ints[j] == target);
            }
        }

        // simulation of some smart work
        int y = 1;
        for (int i = 0; i < n; i++) {
            y += i;
            x[i][i] += y;
        }

        return x;
    }
}

3. Use plugin to generate tests. Set timeout to 180 seconds.

Expected behavior

At least one successful test should be generated.

Actual behavior

Only failing tests were generated.

[alisevych]

Actual for Fuzzing platform - and for Symbolic engine both.
Fuzzing 100% mode 180 sec - produces only error tests.
Symbolic execution 100% mode 180 sec - same.