M2Eclipse & Plugin execution not covered by lifecycle configuration

I was recently forced to update my Eclipse installation to version 3.7 (Indigo). After opening some old projects, I got the following error message:

Plugin execution not covered by lifecycle configuration: org.codehaus.mojo:build-helper-maven-plugin:1.5:add-source (execution: add-source, phase: generate-sources) ... Maven Project Build Lifecycle Mapping Problem

The “build-helper-maven-plugin” simply adds a second source folder:


However, with Indigo and M2Eclipse, the source folder was no longer added, and I got compile errors all over the place…

It took me some time to figure out the right solution:
Just install the “M2Extras / buildhelper” plugin!

You can download it here (Eclipse Update Site):
(The exact directory may vary depending on you exact Eclipse version and the latest available M2Extras release)

@Ignore unit tests immediately if they fail!

In development teams, there is often discussion about using the @Ignore tag for failing tests.

In particular, developers who are very enthusiastic about writing unit tests often tend to be very dogmatic about it. They argue, “A test should never be ignored! It’s better to have the build server on Yellow if tests fail. That way we always have an overview of our problems and are forced to fix them!”

What might sound good at first is not a good idea, at least when it comes to large development teams.

If you have several commits from multiple developers and maybe even additional deliveries from different branches to the main development line, the build will definitely break from time to time. How long does it take to fix such an error? Sometimes it may be easy, but in some cases, it may take days to fix a broken test. Now let’s assume that we have implemented the rule that you should never ignore a test. This means that the build may stay Yellow for a long time.

If another developer now updates his workspace with the latest version from the trunk and runs the unit tests locally, he will see failing tests even if he didn’t make any mistakes! That’s pretty bad itself. But he then checks the build server and, after some time looking around, he realizes it wasn’t his fault, as the server is already in the Yellow state. Should he commit now? If he does, he will receive endless emails from the build server about the broken build state that he didn’t cause. If not, his work and maybe the work of others will be blocked until the test is fixed. In a typical, pretty hectic IT project, with it’s almost impossible to meet deadlines, this is not really an option.

What is the solution?

  1. If you cause a build to break, @Ignore the failing test immediately and commit the change.
  2. Now that the build server is Green again (or Blue in the case of Hudson), start fixing the test.
  3. After you have fixed the test, commit the change and check to see if the build stays Green.
  4. Have some kind of statistic page on the build server that lists all ignored tests – this allows you to easily track the tests that are currently disabled.

Don’t get me wrong: all failing unit tests should be fixed as fast as possible! But my failure when committing a change should never constrain other team members from doing their work.


Large software projects and icons – it depends on the style!

Have you come across similar conversations in the context of large software projects?

Developer: I need an icon for a button.
Boss: You have MS-Paint on your computer. Why don’t you draw it yourself?
Developer: No… I am not a graphic designer… Why don’t we purchase the icons?
Boss: Hmm…We have got an intern, haven’t we? He can do it!
Developer: But he is no graphic designer either… And there are great low-cost icon libraries available to download.
Boss: I wouldn’t know how to book that… The intern will do it!

Sometimes I wonder what makes large companies tick…They spend millions on software and skimp on a few hundred dollars for nice graphics. Unfortunately, the completed applications often look as if an intern has designed the icons.

A leading supplier of icons offers his entire catalogue (approx. 250 sets with around 850,000 icons) for 399 USD. Commissions for individual icons in addition to an existing set cost approx. 50-75 USD per icon. In return you will get designs which are visually pleasing to the end user who interacts with the finished piece of software.

Anyone who allows his developers or interns to design icons, must be crazy.

The Specification Pattern

I recently stumbled across an older article from Greg Young about something called the Specification Pattern. I haven’t heard about it before but the problem sounds familiar to me as I already implemented something similar.

Digging deeper I found an interesting paper from Eric Evans and Martin Fowler explaining the idea in depth: Specifications.

There is also a small Java implementation of the pattern available at Google Code that unforunately seems to be inactive since 2008.

A better keytool II

Have you ever used Java’s keytool? A simplistic command line tool that’s a pain if you use it only once in awhile.

Some time ago I suggested KeyTool IUI as a nice visual replacement for the Java Keytool. The bad news is that the owner sold the software and it’s no longer available. [Update 2011/04/01] Good news! KeyTool IUI is now open source!

But there is another nice open source tool you can use:

It’s a user friendly GUI application for creating, managing and examining keystores, keys, certificates, certificate requests, certificate revocation lists and more.