Fixed tests to give better error messages.

You read the message wrong.

What is the input of the test you failed?

Because 1234567980 (your solution) is not the next bigger number after 1234567890 (the input) ???

You can write them down:

1234567890 # input
1234567891 # +1
1234567892 # +2
...
1234567900 # +10
1234567901 # +11
...
1234567908 # +18, AND THE FIRST TIME WE ENCOUNTER A BIGGER NUMBER WITH THE SAME DIGITS AS THE INPUT VALUE
...
1234567978 # +88
1234567979 # +89
1234567980 # <- your solution, which does have same digits as input, BUT is bigger than 1234567908 --^

Bigger numbers:
Time of your function -0.0001659393310546875
Time of your function -0.00020432472229003906

Execution Timed Out (12000 ms)

how it possible?

When i.m trying to solve this kata in C
i got passes all simple tests and then in random test i got this asser: 1204002415130177602 should be 1204002415130177206
Is is correct? I think that next bigger from "1204002415130177602" should be "1204002415130710267"