Overriding the entrypoint in docker-compose.override.yml does not work

[NeilJ247]

Description

Overriding the entrypoint in docker-compose.override.yml does not work. It uses entrypoint specified in docker-compose.yml instead.

Steps to reproduce the issue:

1. See examples below
2. Run docker-compose up

docker-compose.yml

version: '3.8'

services:
  bash:
    image: bash:latest
    entrypoint: /var/app/entrypoint.sh
    volumes:
      - ./:/var/app

entrypoint.sh

#!/usr/bin/env sh
set -e

echo 'DEFAULT ENTRYPOINT'

docker-compose.override.yml

version: '3.8'

services:
  bash:
    entrypoint: /var/app/override-entrypoint.sh

override-entrypoint.sh

#!/usr/bin/env sh
set -e

echo 'OVERRIDE ENTRYPOINT'

Describe the results you received:

The example docker configs printed out 'DEFAULT ENTRYPOINT' with docker-compose up

Describe the results you expected:

The example docker configs should have printed out 'OVERRIDE ENTRYPOINT' with docker-compose up

Additional information you deem important (e.g. issue happens only occasionally):

Output of docker-compose --version:

docker-compose --version
Docker Compose version v2.0.0-beta.6

Output of docker version:

docker version
Client:
 Cloud integration: 1.0.17
 Version:           20.10.7
 API version:       1.41
 Go version:        go1.16.4
 Git commit:        f0df350
 Built:             Wed Jun  2 11:56:22 2021
 OS/Arch:           darwin/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.7
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       b0f5bc3
  Built:            Wed Jun  2 11:54:58 2021
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.4.6
  GitCommit:        d71fcd7d8303cbf684402823e425e9dd2e99285d
 runc:
  Version:          1.0.0-rc95
  GitCommit:        b9ee9c6314599f1b4a7f497e1f1f856fe433d3b7
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

Output of docker context show:
You can also run docker context inspect context-name to give us more details but don't forget to remove sensitive content.

docker context show      
default

Output of docker info:

docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Build with BuildKit (Docker Inc., v0.5.1-docker)
  compose: Docker Compose (Docker Inc., v2.0.0-beta.6)
  scan: Docker Scan (Docker Inc., v0.8.0)

Server:
 Containers: 5
  Running: 4
  Paused: 0
  Stopped: 1
 Images: 9
 Server Version: 20.10.7
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: d71fcd7d8303cbf684402823e425e9dd2e99285d
 runc version: b9ee9c6314599f1b4a7f497e1f1f856fe433d3b7
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 5.10.25-linuxkit
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 6
 Total Memory: 1.941GiB
 Name: docker-desktop
 ID: 346J:4O6H:QQSS:TD5M:HKLB:7OR7:5OQZ:YRH4:BEQ4:6MWW:VAWT:PPA6
 Docker Root Dir: /var/lib/docker
 Debug Mode: true
  File Descriptors: 80
  Goroutines: 98
  System Time: 2021-08-06T12:32:58.465698937Z
  EventsListeners: 5
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

local environment running on macOS Big Sur version 11.4. Docker desktop 3.5.2

[ndeloof]

This should be addressed by compose-spec/compose-go#164

[ndeloof]

Confirmed issue is fixed with build from HEAD