The other aspect of avoiding clean install is that Maven 3 added support for incremental builds which means invoking clean defeats this feature. It's because of this behavior that if we were to invoke install^H^H verify on this particular build means that the artifacts produced by project1 become available to all other projects if they need them, without requesting said artifacts from a repository. Instead of invoking a goal at a time per project, such as :clean It would mean that the goals are invoked as :clean When we invoke X number of goals each one of them will be invoked in that order per module, that is, when clean install is invoked in a multi-project structure such as. And that particular piece of behavior is executed during the verify phase.ДЄnother thing that may not be obvious at first is the invocation order of goals inside a Reactor. The reactor now being part of core means that some of its features could be deeply linked with the rest of the plumbing, such as attaching the computed artifacts to the current session (the Reactor) so that other modules can fetch artifacts from it instead of fetching from repositories. The lessons learned with this project were later added into core for Maven 3. As a matter of fact it didn't began as part of core but as the maven-reactor-plugin.

For historical reasons (back in the Maven 2 days) we were forced to invoke install all the time if a module in a multi-project build had a dependency on another module, because at the time, multi-project support in Maven was in the early stages. Forward to November 2019, Robert presented about Maven at Devoxx BE ( video), the gist of the talk is adapting to the tool's new behavior. This means every time you invoke install you're also invoking verify, remember that fact. Now note that install is the next phase after verify. In the default (or most common) sequence we've got the following phases: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy.The lifecycle sequence is predetermined (if you want to be nitpicky it can be changed by means of extensions but usually stays the same).

Plugins have the choice to bind their goals to specific phases, so that when a phase becomes active the goals will be executed.

Maven runs a set of lifecycle phases in sequence.

A goal is thus the entry point to perform specific behavior.

Maven plugins (Mojos) expose behavior via goals.

If I can condense what was said back then it would be something like this: Everyone in the session had a great time and the insights shared have been very valuable. With a smirk on his face Robert patiently proceeded to explain the concepts behind Maven lifecycles, goals, plugin bindings, and the execution within the Reactor.

My first reaction to switching was along the lines of 'hold on, the other projects won't compile as they need to resolve dependencies from their siblings'. I was baffled at first because I had no idea that verify existed nor what its purpose is. He also pointed out that I could use verify instead of clean install or just install. Part of what transpired during our sessions was captured at this post. I was facing an issue with building a subset of the Reactor and he showed me the -am -pl command flags. Or so I thought.Д«ack at JCrete 2018 I had the opportunity to talk to Robert Scholte ( about Maven. As a matter of fact when the build contains multiple projects invoking install is a hard requirement, isn't it? Otherwise sibling projects won't be able to find inter-module dependencies. Like many developers when faced with building a Maven project the first reaction is to invoke mvn clean install, after all you find that instruction in almost every README or BUILD file, so why question it? It does not matter if the project is single or contains multiple modules, the instruction is the same. After months of tweeting memes about mvn clean install I decided to get some numbers to see how performance would be affected when switching from one command to the other.

Maven install goal