to add on Joseph answer: if you are in the B directory, then only B is in the reactor (more or less meaning "the list of project being built by this Maven invocation"). My rule of thumb is to never do that and always run from the root. If you want to speedup the build and you know that only B has been modified, you can use maven options such as:
- mvn test -pl :B // it will only build/test the B module - mvn test -pl :B -am // it will build B and all the modules B depends onto - mvn test -rf :B // it resumes the build from B in case B's tests failed , so it will also build modules after B you can note that I add a semi-column before the module name because in case the module is a sub-module (or sub-sub-sub...module), not directly at the parent's root, then it is required. Hope this helps Le jeu. 15 févr. 2024 à 20:55, Joseph Leonard < joseph.leon...@alfasystems.com> a écrit : > Builds in the reactor are always favoured over the m2 repo because the > builds in the reactor will be up-to-date whereas the jar in the repo may be > out of date. > > If you run mvn compile in directory B then you will not be running a multi > module build - and therefore module A will not be in the reactor. This is > why the m2 repo will always be used for module A in this scenario. > > Joe > > -----Original Message----- > From: Siddharth Jain <siddh...@gmail.com> > Sent: Thursday, February 15, 2024 7:50 PM > To: Maven Users List <users@maven.apache.org> > Subject: Re: How does maven resolve inter-module dependencies in a > multi-module build? > > External Email: Please be vigilant and check the contents and source for > signs of malicious activity. > > thanks Joe. but then if classes are available both in the target directory > of module A as well as a jar file in M2 repository which takes precedence? > > also i have noticed that while running mvn compile from the root works, > running mvn compile from the directory of B does not pick up classes from > A's target directory. it only picks up from M2 repo in that case. > > On Thu, Feb 15, 2024 at 11:28 AM Joseph Leonard < > joseph.leon...@alfasystems.com> wrote: > > > Hi Sid, > > It will resolve the classes directory of module A that will have been > > populated during module A's 'compile' build. > > Joe > > > > On 2024/02/15 17:50:44 Siddharth Jain wrote: > > > Hello, > > > > > > I am working on a multi-module Maven build. e.g., I have a root > > > directory containing 3 sub-projects A, B, C and a parent pom defined > > > in the root directory. I notice that I can run mvn compile from the > > > root directory > > and > > > it will build the 3 projects. The projects may have > > > inter-dependencies e.g., B depends on A and let's say C depends on > both A and B. > > > > > > My question is while building B how does maven locate the compiled > > > code > > of > > > A (the dependency) since maven compile by itself does not install > > > the > > built > > > artifact into M2 repository? > > > > > > Sid > > > > > >
