pack stack suggest shows the same stack id twice

[daxhuiberts]

I'm following the documentation and on https://buildpacks.io/docs/concepts/components/stack/ it shows to run pack stack suggest to display a list of recommended stacks. For the minimal Paketo and large Paketo stacks it shows the same io.buildpacks.stacks.bionic stack id. Is this correct?

$ pack stack suggest
Stacks maintained by the community:

    Stack ID: heroku-18
    Description: The official Heroku stack based on Ubuntu 18.04
    Maintainer: Heroku
    Build Image: heroku/pack:18-build
    Run Image: heroku/pack:18

    Stack ID: heroku-20
    Description: The official Heroku stack based on Ubuntu 20.04
    Maintainer: Heroku
    Build Image: heroku/pack:20-build
    Run Image: heroku/pack:20

    Stack ID: io.buildpacks.stacks.bionic
    Description: A minimal Paketo stack based on Ubuntu 18.04
    Maintainer: Paketo Project
    Build Image: paketobuildpacks/build:base-cnb
    Run Image: paketobuildpacks/run:base-cnb

    Stack ID: io.buildpacks.stacks.bionic
    Description: A large Paketo stack based on Ubuntu 18.04
    Maintainer: Paketo Project
    Build Image: paketobuildpacks/build:full-cnb
    Run Image: paketobuildpacks/run:full-cnb

    Stack ID: io.paketo.stacks.tiny
    Description: A tiny Paketo stack based on Ubuntu 18.04, similar to distroless
    Maintainer: Paketo Project
    Build Image: paketobuildpacks/build:tiny-cnb
    Run Image: paketobuildpacks/run:tiny-cnb

[jromero]

The difference between both of the stacks listed with ID io.buildpacks.stacks.bionic are the mixins they provide.

You can see this by looking at the provided mixins of each image:

❯ crane config paketobuildpacks/build:full-cnb | jq -r '.config.Labels["io.buildpacks.stack.mixins"] | fromjson | .[]' | wc -l
     698

❯ crane config paketobuildpacks/build:base-cnb | jq -r '.config.Labels["io.buildpacks.stack.mixins"] | fromjson | .[]' | wc -l
     172

The idea behind this is that buildpacks can specific that they work on io.buildpacks.stacks.bionic but only if certain mixins are provided.