[BUG] Not generating a "cache-to" field when COMPOSE_BAKE=true from yaml

[lucasteligioridis]

Description

With COMPOSE_BAKE=true being the new default now, I happened to spot our caches not being pushed anymore using our cache-to fields setup in our compose.yaml configuration files.

Unsure if there is something we are missing here or something has been misunderstood by me or whether something else needs to be configured on our hosts to enable the behaviour? We were using the buildkit builder setup with the docker-container driver.

We have changed the default for now back to false but want to understand if this is intended and there is some sort of misuse on our end or a bug? Thank you, appreciate any help here! 👍🏼

Steps To Reproduce

1. Create a test compose.yaml file with bare minimum configuration to reproduce this issue.

services:
  my-app:
    build:
      cache_from:
        - type=registry,ref=my-registry.com/my-app:main
      cache_to:
        - type=registry,ref=my-registry.com/my-app:main

2. Run the docker compose command with --verbose mode to show the bake definition output:

docker compose --verbose -f compose.yaml build my-app

3. Debug output will show what the bake definition generated, which is exactly what I'm seeing with no caches being pushed to the registry. This will only show the cache-from fields generating:

TRAC[0000] Docker Desktop integration not enabled
DEBU[0000] bake build config:
{
  "group": {
    "default": {
      "targets": [
        "my-app"
      ]
    }
  },
  "target": {
    "auditmatic": {
      "context": "/var/lib/home/tmp",
      "dockerfile": "/var/lib/home/tmp/Dockerfile",
      "tags": [
        "my-app"
      ],
      "cache-from": [
        "type=registry,ref=my-registry.com/my-app:main"
      ],
      "output": [
        "type=docker,load=true,push=false"
      ]
    }
  }
}

4. Use the raw docker buildx --print command to see how it generates outside of compose and is correct with the fields presented:

{
  "group": {
    "default": {
      "targets": [
        "my-app"
      ]
    }
  },
  "target": {
    "my-app": {
      "context": ".",
      "dockerfile": "Dockerfile",
      "cache-from": [
        {
          "ref": "my-registry.com/my-app:main",
          "type": "registry"
        },
      ],
      "cache-to": [
        {
          "mode": "max",
          "ref": "my-registry.com/my-app:main",
          "type": "registry"
        }
      ],
    }
  }
}

Compose Version

v2.37.1

Docker Environment

Client: Docker Engine - Community
 Version:    28.2.2
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.23.0
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.37.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 5
  Running: 5
  Paused: 0
  Stopped: 0
 Images: 5
 Server Version: 28.2.2
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 05044ec0a9a75232cad458027ca83437aae3f4da
 runc version: v1.2.5-0-g59923ef
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  userns
  cgroupns
 Kernel Version: 6.11.0-1015-gcp
 Operating System: Ubuntu 24.04.2 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 31.34GiB
 Name: ferocia-builder-3004
 ID: 3f43c53f-e2ed-4e3c-b5a2-3924b66da522
 Docker Root Dir: /var/lib/docker/2000.2000
 Debug Mode: false
 Experimental: true
 Insecure Registries:
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false
 Default Address Pools:
   Base: 172.17.0.0/20, Size: 26
   Base: 172.17.16.0/20, Size: 26
   Base: 172.17.32.0/20, Size: 26

Anything else?

No response