I checked out the trunk but cannot build it. It seems people use dependencies that are not yet deployed. When I try and use older versions of the hpi-plugin i get "cannot get checksum".
Try and checkout the trunk and delete the corresponding folders in your local maven repo and the build will fail. If those deps get installed by jenkins and therefore the jenkins build succeeds, consider adding "deploy" to the jenkins configuration to enable the community to build, too.

Missing:
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1) org.jvnet.maven-jellydoc-plugin:maven-jellydoc-plugin:jar:1.5

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.jvnet.maven-jellydoc-plugin -DartifactId=maven-jellydoc-plugin -Dversion=1.5 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.jvnet.maven-jellydoc-plugin -DartifactId=maven-jellydoc-plugin -Dversion=1.5 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) org.jenkins-ci.tools:maven-hpi-plugin:maven-plugin:1.78
2) org.kohsuke.stapler:maven-stapler-plugin:jar:1.16
3) org.jvnet.maven-jellydoc-plugin:maven-jellydoc-plugin:jar:1.5

2) org.kohsuke.stapler:stapler-groovy:jar:1.169

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.kohsuke.stapler -DartifactId=stapler-groovy -Dversion=1.169 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.kohsuke.stapler -DartifactId=stapler-groovy -Dversion=1.169 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) org.jenkins-ci.tools:maven-hpi-plugin:maven-plugin:1.78
2) org.kohsuke.stapler:stapler-groovy:jar:1.169

3) org.jvnet.maven-jellydoc-plugin:jellydoc-annotations:jar:1.5

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.jvnet.maven-jellydoc-plugin -DartifactId=jellydoc-annotations -Dversion=1.5 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.jvnet.maven-jellydoc-plugin -DartifactId=jellydoc-annotations -Dversion=1.5 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) org.jenkins-ci.tools:maven-hpi-plugin:maven-plugin:1.78
2) org.kohsuke.stapler:maven-stapler-plugin:jar:1.16
3) org.jvnet.maven-jellydoc-plugin:maven-jellydoc-plugin:jar:1.5
4) org.jvnet.maven-jellydoc-plugin:jellydoc-annotations:jar:1.5

4) org.kohsuke.stapler:stapler-jelly:jar:1.169

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.kohsuke.stapler -DartifactId=stapler-jelly -Dversion=1.169 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.kohsuke.stapler -DartifactId=stapler-jelly -Dversion=1.169 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) org.jenkins-ci.tools:maven-hpi-plugin:maven-plugin:1.78
2) org.kohsuke.stapler:stapler-groovy:jar:1.169
3) org.kohsuke.stapler:stapler-jelly:jar:1.169

5) org.jvnet.maven-jellydoc-plugin:taglib-xml-writer:jar:1.5

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.jvnet.maven-jellydoc-plugin -DartifactId=taglib-xml-writer -Dversion=1.5 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.jvnet.maven-jellydoc-plugin -DartifactId=taglib-xml-writer -Dversion=1.5 -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) org.jenkins-ci.tools:maven-hpi-plugin:maven-plugin:1.78
2) org.kohsuke.stapler:maven-stapler-plugin:jar:1.16
3) org.jvnet.maven-jellydoc-plugin:maven-jellydoc-plugin:jar:1.5
4) org.jvnet.maven-jellydoc-plugin:taglib-xml-writer:jar:1.5

----------
5 required artifacts are missing.

for artifact:
org.jenkins-ci.tools:maven-hpi-plugin:maven-plugin:1.78

from the specified remote repositories:
repo.jenkins-ci.org (http://repo.jenkins-ci.org/public/),
central (http://repo1.maven.org/maven2),
maven.jenkins-ci.org (http://maven.jenkins-ci.org/content/repositories/snapshots/)