Skip to content

bug(sandbox): arm64 remote cluster fails on x86_64 host without DOCKER_PLATFORM and missing default policy file #5

@pimlock

Description

@pimlock

Summary

Creating a sandbox against an arm64 remote host from an x86_64 machine fails unless DOCKER_PLATFORM=aarch64 is set manually. After using that workaround, sandbox startup can still fail because dev-sandbox-policy.yaml is missing.

Actual behavior

  • navigator sandbox create --remote spark.local -- claude prompts to create a cluster, then cluster startup fails with:
    • cluster container is not running while waiting for kubeconfig
    • exec /usr/local/bin/cluster-entrypoint.sh: exec format error
  • With DOCKER_PLATFORM=aarch64, cluster creation succeeds, but sandbox startup later fails with:
    • failed to read sandbox policy from dev-sandbox-policy.yaml
    • No such file or directory (os error 2)

Expected behavior

  • Navigator should detect/handle host vs target architecture automatically when creating remote clusters, without requiring users to set DOCKER_PLATFORM manually.
  • If dev-sandbox-policy.yaml is required, it should be generated automatically (or a sensible default should be used) so sandbox startup does not fail.

Reproduction

  1. Use an x86_64 machine.
  2. Run navigator sandbox create --remote spark.local -- claude against a spark host (arm64).
  3. Observe cluster creation failure with exec format error.
  4. Retry with DOCKER_PLATFORM=aarch64 navigator sandbox create --remote spark.local -- claude.
  5. Observe subsequent sandbox policy file error (dev-sandbox-policy.yaml missing).

Environment

  • Local host arch: x86_64
  • Remote host arch: arm64 (spark)
  • Command: navigator sandbox create --remote spark.local -- claude

Notes

This may be easy to miss on macOS because architecture assumptions may differ there.


Originally by @drew on 2026-02-10T17:32:13.224-08:00

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions