Comment by linkage
20 hours ago
Half the point of containerization is to have reproducible builds. You want a build environment that you can trust will be identical 100% of the time. Your host machine is not that. If you run `pacman -Syu`, you no longer have the same build environment as you did earlier.
If you now copy your binary to the container and it implicitly expects there to be a shared library in /usr/lib or wherever, it could blow up at runtime because of a library version mismatch.
Nobody is suggesting to copy the binary to the Docker container.
When developing locally, use `cargo test` in your cli. When deploying to the server, build the Docker image on CI. If it takes 5 minutes to build it, so be it.