Image buildpack references without tag do not default to latest version

[dmikusa]

When building an image with ./mvnw spring-boot:build-image if I add two buildpacks to my configuration using the format to specify an image, like:

<buildpacks>
    <buildpack>gcr.io/paketo-buildpacks/bellsoft-liberica</buildpack>
    <buildpack>gcr.io/paketo-buildpacks/java-native-image</buildpack>
</buildpacks>

I get an error:

[ERROR] Failed to execute goal org.springframework.boot:spring-boot-maven-plugin:2.5.5:build-image (default-cli) on project demo: Execution default-cli of goal org.springframework.boot:spring-boot-maven-plugin:2.5.5:build-image failed: Different digests IDs provided -> [Help 1]

Upon inspecting the output of docker images it shows that two very old versions of the first buildpack were downloaded. Ignore the 41 years ago, it's the 1.0/1.1 which are the problem. Those are the original two versions of the buildpack.

gcr.io/paketo-buildpacks/bellsoft-liberica   1.1.0      0b37a7390ca5   41 years ago   692MB
gcr.io/paketo-buildpacks/bellsoft-liberica   1.0.0      1fc7ae444343   41 years ago   681MB

It is easy enough to set a version and work around this, but the present behavior isn't what I'd say is the expected default behavior. I think fetching the "latest" version would be what's expected. This is also what the pack cli does in this situation.