How can bamboo re-use build results?

Question

So I have the following scenario:

-I have a successful build on master on commit A

-I have a successful build on branch develop on commit B, who's parent is A

-I merge B into A using a fastforward commit, so that master now points to B

With my plan branches setup on Bamboo, it will trigger a new build for B even though it has already built it. Can bamboo be configured to re-use the build result for a commit with an existing build?

nbelakovski · Answer

I agree with you 100% that each commit should have its own build, but in the current system, as I described it in my note, there are actually two builds for one commit, which could be different if, for example, the current timestamp is used in the build process, or if the build accesses information in database which has changed between runs.

In the scenario I described, there is no AB commit. Master gets fastforwarded onto B, which already passed, no merge commit is created, and so I would think that the Bamboo plan's master branch would get auto-magically updated to have a build number that points to the successful B build.

Does that make sense?

Gabriel Ribeiro · Answer

Hi Nickolai,

I'm afraid not. From my perspective, one of the main benefits of continuous integration is to have a different build for each commit allowing you to have less back-tracking when you try to find the change responsible for a red build.

In the proposed approach, what could guarantee that if A and B are passing, then AB will also pass?

Even if there was a way, I wouldn't do that.

Don't you agree?

thanks.