logback-classic makes use of Groovy. This currently causes a complex situation with the Eclipse Groovy plugins and other Eclipse plugins which all use logback-classic. In particular, the support for multiple versions of Groovy compilers in the Eclipse Groovy project and the interaction with the logback-classic Groovy and they way that the Eclipse Equinox container binds the different bundles to each other seems to be causing problems. As a result, the Eclipse Groovy plugins currently declare an incompatibility with the m2e slf4j-over-logback plugin which prevents both plugins to be installed in Eclipse at the same time.

Now this may all sound like "why should we care if this is about the Eclipse world?". The problem is, that it is currently less than clear what would be a good approach to tackle the problem. Besides other things, it has been suggested to adjust the way that Eclipse Orbit bundles the logback-classic JAR. In the latest comment, one person has identified that Groovy Support in logback is actually disabled due to incompatibility with Java 9 and the question came up if it maybe should be dropped entirely.

Here is a list of related issues in different projects to illustrate the scope of the problem:

• m2e slf4j-over-logback vs. groovy vs. Eclipse classloader eclipse-m2e/m2e-core#269
• Groovy Eclipse 4.2.0 <-> m2e console groovy/groovy-eclipse#1275
• Incompatibility between Groovy Eclipse Plugin and PMD Plugin pmd/pmd-eclipse-plugin#134
• Eclipse 2021-03 (4.19) won't start after installing https://dist.springsource.org/snapshot/GRECLIPSE/e4.19 groovy/groovy-eclipse#1237
• https://bugs.eclipse.org/bugs/show_bug.cgi?id=574922 (logback-classic bundle definition causes problems for multiple downstream projects)

It would be great if you could have a look and maybe provide an additional opinion how the problems could be resolved.