The second factor is related to the dependency management tool. I'm familiar with the Java environment and, since its first release, I've been using Maven to explicitly declare and isolate dependencies.

Maven does it, concentrating everything into a file named pom.xml, where you can specify the library or framework you want to use and the exact version. Maven will compile and build your code by downloading the JARs you need from the internet (Maven repositories). Nevertheless, there are a lot of dependency management tools for all modern programming languages, such as Ivy, Gradle, Gemfiles, Bundler, and Godm.

Long story short, have a dependency management tool that ensures consistency in the build.