Description

docker-compose will error with a misleading message when stdin is not a TTY but stdout is a TTY, and stdin_open: true. docker doesn't have this problem.

Steps To Reproduce

1. compose.yaml:

services:
  main:
    image: debian:trixie
    command: ['cat']
    stdin_open: true

2. echo a | docker-compose run --rm main | cat
   You will get an a as output.
3. echo a | docker-compose run --rm main
   I expect to get an a as output, because echo a | docker run -i --rm debian:trixie cat also outputs an a. But I got the input device is not a TTY, which is misleading --- I did not ask for a TTY, why is docker-compose complaining the input device not being a TTY? And it's very hard to guess that the actual problem is related to stdout (being a TTY), not stdin.

Compose Version

# docker compose version
Docker Compose version 2.26.1-4
# docker-compose version
Docker Compose version 2.26.1-4

Docker Environment

Client:
 Version:    26.1.5+dfsg1
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  0.13.1+ds1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  2.26.1-4
    Path:     /usr/libexec/docker/cli-plugins/docker-compose
...
 Kernel Version: 6.12.43+deb13-amd64
 Operating System: Debian GNU/Linux 13 (trixie)
...

Anything else?

No response