Hi Guix! This patch series adds the maven-build-system, at last! You can find the patches on the wip-maven-build-system branch of my repository, at https://framagit.org/tyreunom/guix/-/tree/wip-maven-build-system I haven't sent the patches on this mailing because there are ~100 of them. If you prefer, I'll send the series with git send-patch. Here is a summary of the changes: guix: java-utils: Add Maven-related phases. This patch adds some functionalities to guix/build/java-utils.scm, in particular the install-from-pom and install-pom-file functions that are phases you can use instead of the install phase. As their name suggests, they install a package from a pom.xml file to a maven repository directory structure in lib/m2. install-pom-file only installs a single pom.xml file, instead of the file and its jar. gnu: java-asm: Remove dependency on bnd libraries. ... gnu: java-jarjar: unbundle maven-plugin-api. This small series of patches improves the bootstrap of java-junit by not relying on bundled libraries (binaries), by enabling tests in junit and by reducing the number of dependencies that must be built before junit. Junit is now fully bootstrapped. gnu: java-junit: Install from pom file. This patch converts junit and its dependencies to the maven repository structure. It also takes care of changing junit's dependents that had a hardcoded path to the junit jar file. gnu: Add apache-parent-pom-13. ... gnu: Add maven-components-parent-pom-21. This series adds many parent pom packages to a new file, maven-parent-pom.scm. A parent pom is a single pom.xml file that contains information about a project. Actual packages can then reference these files to inherit some or all of these information. gnu: java-commons-lang3: Update to 3.9. ... gnu: maven: Install from pom file. These patches update some dependencies of maven and the maven build system, and convert them so they are installed in the maven repository structure. gnu: maven-shared-utils: Fix /bin/sh invocation. gnu: java-modello-core: Propagate inputs. These two patches implement fixes that are required later on. gnu: Add java-plexus-digest. ... gnu: Add maven-jar-plugin. This patch series adds more packages that are maven plugins or their dependencies. Maven doesn't do anything by itself, it's simply a dependency/lifecycle manager. It requires plugins to actually do things such as compiling, creating a jar archive, installing, testing, etc... This is what these patches implement. guix: Add maven-build-system. The actual commit that adds the maven-build-system :) In the end, the maven-build-system only has the very basic plugins by default, but it is able to compile, test and install a simple hello world example application, generated by maven (see test.scm attached). Next step is building the maven-plugin-plugin, which is the plugin that builds other plugins. Currently the plugins are built with a custom plugin.xml generator that uses a buggy java parser, so I don't want to rely on it for other plugins. Note that we can't use the maven-plugin-plugin to build any of the current plugins, since they are needed to build themselves... I also noticed that our maven is acting weird wrt lifecycles: it seems to be doing some test-related work during the build step, and rebuilds in the test and install steps. This is weird, but I'm not sure how to fix. Re-building maven with the maven-build-system might give as a better version of maven. I don't really want to investigate that now, that's why I'm sending the patch series anyway. Hope you enjoy!