Guidance on Maven build

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Hello, this is a call for assistance in getting a Java Maven project to build under Nix. The approach taken follows that described here:

https://ryantm.github.io/nixpkgs/languages-frameworks/maven/

The project in question is the agent based transport simulator MATSim example project, which I have forked and to which I have added a flake and a Makefile if you wish to have a hands-on look:

The flake is

{
  inputs = {
    flake-utils.url = "github:numtide/flake-utils";
    nixpkgs.url = "nixpkgs/nixos-unstable";
  };
  
  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; };

        # mvn2nix plugin
        maven-repository = (pkgs.buildMaven ./project-info.json).repo;
        
        matsim = pkgs.stdenv.mkDerivation rec {
          pname = "matsim-example-project";
          version = "0.0.1-SNAPSHOT";
          
          src = ./.;
          buildInputs = [ pkgs.maven ];
          
          buildPhase = ''
          echo "Using repository ${maven-repository}"
          mvn --offline -Dmaven.repo.local=${maven-repository} package;
          '';

          installPhase = ''
          install -Dm644 target/${pname}-${version}.jar $out/share/java
          '';
        };

        # double invocation
        maven-repository-2 = pkgs.stdenv.mkDerivation {
          name = "maven-repository";
          buildInputs = [ pkgs.maven ];
          src = ./.; # or fetchFromGitHub, cleanSourceWith, etc
          buildPhase = ''
          mvn package -Dmaven.repo.local=$out
          '';

          # keep only *.{pom,jar,sha1,nbm} and delete all ephemeral files
          # with lastModified timestamps inside
          installPhase = ''
          find $out -type f \
          -name \*.lastUpdated -or \
          -name resolver-status.properties -or \
          -name _remote.repositories \
          -delete
          '';

          # don't do any fixup
          dontFixup = true;
          outputHashAlgo = "sha256";
          outputHashMode = "recursive";
          # replace this with the correct SHA256
          # outputHash = pkgs.lib.fakeSha256;
          outputHash = "sha256-URq6vNUlF5tttDUeZ97o8IPMZgRMA17MpHmZdeV4wDw=";
        };

        matsim-2 = pkgs.stdenv.mkDerivation rec {
          pname = "matsim-example-project";
          version = "0.1.0-SNAPSHOT";
          
          src = ./.;
          buildInputs = with pkgs; [ maven jre ];
          nativeBuildInputs = with pkgs; [ makeWrapper ];
          
          buildPhase = ''
          echo "Using repository ${maven-repository-2}"
          mvn --offline -Dmaven.repo.local=${maven-repository-2} package;
          # mvn --offline -Dmaven.repo.local=${maven-repository-2} install;
          '';

          installPhase = ''
          mkdir -pv $out/share/java $out/bin
          install -Dm644 target/${pname}-${version}.jar $out/share/java
          makeWrapper ${pkgs.jre}/bin/java $out/bin/${pname} \
                      --add-flags "-cp $out/share/java/${pname}-${version}.jar"
          '';
          
        };

      in rec {        
        packages.default = packages.matsim;
        packages.matsim = matsim;
        packages.matsim-2 = matsim-2;
        packages.maven-repository = maven-repository;
        packages.maven-repository-2 = maven-repository-2;
        
        devShell =  pkgs.mkShell {
          buildInputs = [
            pkgs.maven
            pkgs.jre
          ]; 
        };        
      }
    );
}

The “Double Invocation” method succeeds

nix build .#matsim-2
# update sha
nix build .#matsim-2

(or make matsim-2), but I would prefer not to have to manually to update the sha for each build.

The “buildMaven with NixOS/mvn2nix-maven-plugin”

mvn org.nixos.mvn2nix:mvn2nix-maven-plugin:mvn2nix
nix build .#matsim

(or make matsim) fails with

       > [ERROR] Failed to execute goal on project matsim-example-project: Could not resolve 
dependencies for project org.matsim:matsim-example-project:jar:0.1.0-SNAPSHOT: Failed to 
collect dependencies at org.matsim:matsim:jar:15.0 -> org.geotools:gt-main:jar:29.0 -> 
org.apache.commons:commons-text:jar:1.10.0: Failed to read artifact descriptor for 
org.apache.commons:commons-text:jar:1.10.0: Cannot access osgeo 
(https://repo.osgeo.org/repository/release/) in offline mode and the artifact 
org.junit:junit-bom:pom:5.9.1 has not been downloaded from it before. -> [Help 1]

which might suggest that the mvn2nix plugin is failing at capturing all of the dependencies.

Any advice, tips, leads on how to proceed are very welcome.