If any build_as_root command fails, composer silently does not get installed in the container.

Example:

name: testsite
recipe: wordpress

config:
  php: '8.2'
  via: apache
  database: mysql
  webroot: .
  composer_version: 2
  xdebug: false

services:
  appserver:
    xdebug: false
    build_as_root:
      - exit 1

$ lando rebuild -y --debug

The only hint something went wrong are these debug lines, which doesn't really tell us what happened/which command failed.

  local process pid11 running /home/xxxx/.lando/bin/docker-compose-v2.31.0 exec appserver /helpers/exec-multiliner.sh ZXhpdCAx cstdio=inherit, silent=false, mode=spawn, detached=false +2ms
  local process pid11 finished with exit code 1  +35ms
  local ERROR   +1ms

Even if something goes wrong, that should not prevent composer from being installed:

$ lando composer --version

OCI runtime exec failed: exec failed: unable to start container process: exec: "composer": executable file not found in $PATH