Setting variables at build-time can provide valuable metadata to our application that wasn’t available when writing the code or even at runtime. We can control feature-flags, or build information, like a version number, without updating the Go-code constantly.
I’m a great proponent of building our own tools. As developers, we perform many repetitive tasks, big and small. Many of these tasks might be made easier by using an appropriate tool instead. We often concentrate too much on solving more significant problems. Sometimes it doesn’t even need to be a real problem for a tool to be valuable. We have to find the sweet spots in our workflow.