I have a large multi-module project which takes about an hour to build from clean in Jenkins.
I am using Maven CI-friendly versioning using ${revision} for all module versions in the multi-module project, and I'm passing in something like -Drevision=${BUILD_NUMBER} from Jenkins.
This works fine, but it is so inefficient when deployed across a team of 20-ish, with a new build for every Pull Request. Who wants to wait an hour every time a single line of code changes?!?
How can I get incremental build working with my project structure?
The obvious problem with the 'incremental build' tickbox is that when I build the changed modules (e.g. version 5) they will all depend on unchanged modules also with version 5, yet the last version that was actually built may be 1,2,3 or 4.
So ${revision} across the whole multi-module project will break incremental building
My other issue is that I am using multiple slaves, meaning I cannot simply rely on the file system being unchanged since last build (same Maven Local Repo, same working tree, etc).
In order to share unchanged artifacts between builds on different slaves I'd have to either use the Maven Repo (e.g. Nexus), or have some kind of file copy over SSH (e.g. each build transfers back up to Master and then down to slaves)