fix: LD_ASSUME_KERNEL for Docker 18.09 compatibility (Issue #508)

[claw-mini-zz]

Summary

Fix for Issue #508: Docker 18.09 兼容性问题

Problem

Docker 18.09 runs on Linux kernel 4.x which doesn't support clone3(). glibc 2.34+ defaults to clone3, causing RuntimeError: can't start new thread when creating threads in Python.

Solution

Set LD_ASSUME_KERNEL=2.33.0 environment variable to force glibc to use the legacy clone() system call instead of clone3().

Changes

1. server/src/services/docker.py: Add LD_ASSUME_KERNEL=2.33.0 as default environment variable in _build_labels_and_env method
2. components/execd/bootstrap.sh: Add export LD_ASSUME_KERNEL=2.33.0 for execd daemon

Testing

This fix should allow OpenSandbox to work on:

• Docker 18.09
• Linux kernels < 5.9
• Systems with glibc < 2.34

---

Fixes #508

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Preserve caller-provided LD_ASSUME_KERNEL

This change unconditionally sets LD_ASSUME_KERNEL=2.33.0, which overwrites any value a caller passes in CreateSandboxRequest.env; sandbox containers always execute this script because Docker provisioning uses entrypoint=[BOOTSTRAP_PATH] in server/src/services/docker.py. In workloads that intentionally set a different LD_ASSUME_KERNEL (or need to disable it), the requested environment is ignored, which can cause runtime incompatibilities for those images. Treat this as a default-only value (set it only when unset) so explicit user configuration remains authoritative.

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