Devpod build fails when using Multi-Stage build with a Feature

[joshbrooks]

What happened?

In my dev environment I use a multistage build, like this

FROM mcr.microsoft.com/devcontainers/python:1-3.12-bookworm AS builder
# ...
FROM builder AS final
# ...

I also have in my devcontainer.json a features clause to add node

	"features": {
		"ghcr.io/devcontainers/features/node:1": {
			"installYarnUsingApt": true,
			"version": "lts",
			"nvmVersion": "latest"
		}
	},

When I try to start a workspace (debug on) it fails. this debug log indicates that an incorrect dockerfile is generated:
Note line 3 FROM AS final.

{"type":"data","data":{"time":"2024-11-29T11:14:54.363901867+09:00","message":"Creating extended Dockerfile /var/home/josh/.devpod/agent/contexts/default/workspaces/education-git-rc-2-0/content/.devcontainer/python/.devpod-internal/Dockerfile-with-features with content: 
 # syntax=docker.io/docker/dockerfile:1.4
ARG _DEV_CONTAINERS_BASE_IMAGE=placeholder
FROM  AS final

FROM $_DEV_CONTAINERS_BASE_IMAGE AS dev_containers_target_stage

USER root

COPY ./.devpod-internal/ /tmp/build-features/
RUN chmod -R 0755 /tmp/build-features && ls /tmp/build-features

RUN \\
echo \"_CONTAINER_USER_HOME=$(getent passwd root | cut -d: -f6)\" >> /tmp/build-features/devcontainer-features.builtin.env && \\
echo \"_REMOTE_USER_HOME=$(getent passwd vscode | cut -d: -f6)\" >> /tmp/build-features/devcontainer-features.builtin.env

ENV NVM_DIR=/usr/local/share/nvm
ENV NVM_SYMLINK_CURRENT=true
ENV PATH=/usr/local/share/nvm/current/bin:${PATH}
RUN cd /tmp/build-features/0 \\
&& chmod +x ./devcontainer-features-install.sh \\
&& ./devcontainer-features-install.sh



ARG _DEV_CONTAINERS_IMAGE_USER=root
USER $_DEV_CONTAINERS_IMAGE_USER","level":"debug"}}
{"type":"data","data":{"time":"2024-11-29T11:14:54.365453753+09:00","message":"Creating docker-compose build /var/home/josh/.devpod/agent/contexts/default/workspaces/education-git-rc-2-0/.docker-compose/docker-compose.devcontainer.build-54.yml with content:
 services:
  django:
    build:
      context: /var/home/josh/.devpod/agent/contexts/default/workspaces/education-git-rc-2-0/content/.devcontainer/python
      dockerfile: /var/home/josh/.devpod/agent/contexts/default/workspaces/education-git-rc-2-0/content/.devcontainer/python/.devpod-internal/Dockerfile-with-features
      args:
        _DEV_CONTAINERS_BASE_IMAGE: final
        _DEV_CONTAINERS_IMAGE_USER: root
        BUILDKIT_INLINE_CACHE: \"1\"","level":"debug"}}

What did you expect to happen instead?

Multistage builds work correctly with features. I tested

How can we reproduce the bug? (as minimally and precisely as possible)

• Create a multistage dockerfile
• Add a feature to a devcontainer.json referencing that dockerfile

My devcontainer.json:

{
	"name": "Education",
	"dockerComposeFile": ["../compose.yml"],
	"service": "django",
	"workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
	"shutdownAction": "none",
	"customizations": {
		"vscode": {
			"extensions": [
				"ms-python.python",
				"ms-python.debugpy",
				"charliermarsh.ruff",
				"Vue.volar",
				"eamodio.gitlens",
				"ms-python.vscode-pylance"
			]
		}
	},
	// Make npm features available in this python dev container
	"features": {
		"ghcr.io/devcontainers/features/node:1": {
			"installYarnUsingApt": true,
		        "version": "lts",
	 		"nvmVersion": "latest"
	 	}
	 }
}

Local Environment:

• DevPod Version: 0.6.0
• Operating System: linux
• ARCH of the OS: AMD64

DevPod Provider:

• Local/remote provider: docker

Anything else we need to know?

As workarounds, commenting out features or removing the multistage build requirement both work.

[pascalbreuninger]

Hey @joshbrooks, thanks for opening the issue. We'll look into it.
Just to get the complete picture here, could you also provide your compose.yml file please?