Getting started with plugin development

[Mike Thompson]

Hello,

I am new to this list (although a long time OSM mapping contributor).

I am trying to develop a JOSM plugin following the steps here[0].

I was able to successfully (I think - I didn't notice any error messages)
check out the plugin environment into an empty directory called josm per
the instructions (specifically /home/<my username>/josm

However, when I attempt:
$ cd josm/core
$ ant
to compile josm core, I get the following message:

[ivy:resolve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:resolve] ::          UNRESOLVED DEPENDENCIES         ::
[ivy:resolve] ::::::::::::::::::::::::::::::::::::::::::::::
[ivy:resolve] :: org.jacoco#org.jacoco.ant;0.8.6-SNAPSHOT: not found
[ivy:resolve] ::::::::::::::::::::::::::::::::::::::::::::::

I am running Ubuntu 16.04.7 LTS

I tried
$ sudo apt update
$ sudo apt upgrade

And then retried the compile.  However, I got the same message.

I tried:
$ ant -v

But even with the verbose switch, I didn't notice any additional
information that was helpful.

A couple of years ago I was able to develop a plugin (nothing worthy of
release to the community, but at least it ran and showed a dialog with
"Hello World").  Since JOSM has changed a lot in that time, I completely
removed that JOSM environment, and started over.

Any help would be greatly appreciated.

Thanks,
Mike


[0] https://josm.openstreetmap.de/wiki/DevelopersGuide/DevelopingPlugins