Ask HN: Landing page vs. Open-source MVP

I have an idea to work on and this idea aims to solve a problem that I face. I'm curious how many people face the same pain point as I do and would even use my product as their solution.

I'm considering between building a landing page to collect emails and building an open-source project on Github to see its traction.

A landing page will take probably 1-2 days. Building a project will take a longer time - might take 3, 4 weeks to build something that is presentable - but I think it is easier for people to see how the product works and understand what it is trying to solve.

What do you think is a better approach?

On top of that, supposed I have talked to a few friends and they understand the pain point but are vague on whether they will pay for a solution, which approach (landing page or open-source project) should I use?