Assertion `tmp == c[i * N + j]' failed

[debtanu09]

Hi I'm trying to test my GPGPU Sim build and I'm following the blog https://coffeebeforearch.github.io/2020/03/30/gpgpu-sim-1.html
On following the instructions, I'm getting
mmul: mmul.cu:42: void verify_result(std::vector&, std::vector&, std::vector&, int): Assertion `tmp == c[i * N + j]' failed.
Aborted (core dumped)

My configuration-
intel i5-8265U
8 GB DDR4 RAM
Ubuntu 20.04 LTS
gcc 10.2
Cuda build version - 11.2
Please help