Raise the minimum supported version of Gradle to 7.3

[wilkinsona]

No description provided.

[wilkinsona]

We need to use Gradle 7.3 as a minimum. While Gradle 7.2 runs on Java 17, it falls over when it encounters Java 17 bytecode such as in our Gradle plugin.

[vpavic]

This doesn't sound right to me.

The cost of the upgrade to Spring Framework 6.x/Spring Boot 3.x will be high enough due to the steep increase of the baseline, and Gradle's toolchains support can actually help there by preventing that cost from spilling into the build infrastructure.

However by building the plugin using Java 17 you're negating that advantage.

[wilkinsona]

By the time Spring Boot 3 has GAed, Gradle 7.3 will be 12 months old. If anything, further increases of the minimum supported version of Gradle will be made during the course of Boot 3.0's development. We may even get to the point where we support the last Gradle 7.x release and Gradle 8.x, depending on their release schedule.

[vpavic]

Sorry, I wasn't clear enough - I was referring to the fact that the build plugin is built using Java 17 effectively makes it impossible to leverage Gradle toolchains and keep the pipeline running on older version of Java.

[wilkinsona]

This change is for Spring Boot 3.0 where the entire portfolio will have a Java 17 baseline. Why would you want to run Gradle on an older version of Java?

[vpavic]

Because something else in the build pipeline (other plugins etc.) isn't ready for upgrade?

[wilkinsona]

With 3.0's GA almost a year away, we'd prefer to cross that bridge if and when we come to it. In the meantime, please try out the snapshots and milestones once they're available and report any problems you find to the relevant projects.