Python Docker:已生成但无法执行的web服务

我正在尝试用docker构建Django web服务。
docker文件是

ENV DockerHOME=/home/xs1_glaith/cafegard

RUN mkdir -p $DockerHOME

WORKDIR $DockerHOME

ENV PYTHONDONTWRITEBYTECODE=1
ENV PYTHONUNBUFFERED=1

docker compose文件如下所示

    version: "3.9"

services:
  db:
    image: postgres
    volumes:
    - ./data/db:/var/lib/postgresql/data
    environment:
      - POSTGRES_DB=postgress
      - POSTGRES_USER=postgress
      - POSTGRES_PASSWORD=postgress
  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
    - .:/home/xs1_glaith/cafegard
    ports:
    - "8000:8000"
    depends_on:
      - db
    
    COPY . $DockerHOME
    
    RUN pip install --upgrade pip
    RUN pip install -r $DockerHOME/requirements.txt
    
    EXPOSE 8000
    CMD python manage.py runserver

最后，结果是

Starting cafegard_db_1 ... done
Creating cafegard_web_run ... done
Error response from daemon: OCI runtime create failed: container_linux.go:367: starting container process caused: exec: ".": executable file not found in $PATH: unknown
ERROR: 1

我真的不明白问题出在哪里，或者问题出在哪里