Root cause: patch_ops.sh uses relative paths (./api_server.py, ./reasoning/, etc.)
but never cd's into its own directory. Dockerfile sets WORKDIR=/workspace/ and runs
'bash /workspace/qwen3_6_scripts/patch_ops.sh', so cwd=/workspace/ at execution time.
Every 'cp ./xxx' and 'deploy ./xxx' silently fails because the files are at
/workspace/qwen3_6_scripts/xxx, not /workspace/xxx. Without set -e, the script
completes with exit 0, Docker build succeeds, but NO patches are actually applied.
Result: the original vllm 0.6.3 api_server.py runs (no reasoning-parser support),
sees --reasoning-parser qwen3 as unrecognized, and exits with argparse error.
Fix:
1. cd "$(dirname "$0")" at script start → all ./paths resolve correctly
2. set -eo pipefail → any failed cp now fails the build immediately