Sandbox exec returns 500 and leaves execution stuck queued

[rblalock]

Summary

A plain agentuity cloud sandbox exec against a fresh idle sandbox is returning 500 Internal Server Error for a trivial command.

This reproduces outside Coder Hub, so it looks like a sandbox/platform issue rather than a Coder-specific bug.

Minimal repro

ORG_ID="org_2u8RgDTwcZWrZrZ3sZh24T5FCtz"

mkdir -p /tmp/agentuity-sbx-repro

SANDBOX_ID="$(
  agentuity cloud sandbox create \
    --dir /tmp/agentuity-sbx-repro \
    --runtime bun:1 \
    --name simple-exec-repro \
    --org-id "$ORG_ID" \
    --json | jq -r '.sandboxId'
)"

echo "sandbox: $SANDBOX_ID"

agentuity cloud sandbox exec "$SANDBOX_ID" --timeout 30s -- bash -lc 'test -s /etc/hosts'

Actual result

The exec returns:

[ERROR] APIErrorResponse: Internal Server Error

  context:
      sessionId: 'sess_bcffca7796c84d97b307f1adba4508aa',
      status: 500,
      url: 'https://catalyst-usc.agentuity.cloud/sandbox/sbx_37e7bbc6924823cf7aa8b7bdb2d4ccfbc7ba1f2fe7ed4d3b14531bf310c0/execute'

Follow-up verification

After the failed exec, the sandbox shows a queued execution instead of a completed or failed one:

agentuity cloud sandbox execution list "$SANDBOX_ID" --org-id "$ORG_ID" --json

Example result:

{
  "executions": [
    {
      "executionId": "exe_858b1e8460fd1a547356c69e55b2c7e8044411ee74723cdf366050b55076",
      "sandboxId": "sbx_37e7bbc6924823cf7aa8b7bdb2d4ccfbc7ba1f2fe7ed4d3b14531bf310c0",
      "status": "queued"
    }
  ]
}

And:

agentuity cloud sandbox execution get exe_858b1e8460fd1a547356c69e55b2c7e8044411ee74723cdf366050b55076 --org-id "$ORG_ID" --json

shows the expected command payload:

{
  "status": "queued",
  "command": ["bash", "-lc", "test -s /etc/hosts"]
}

Expected result

The command should complete quickly with exit code 0, or at minimum transition to a terminal execution state instead of returning a raw 500 and leaving the execution stuck in queued.

Notes

• Reproduced on April 17, 2026.
• Reproduced from the CLI without Coder Hub in the path.
• Runtime used: bun:1.
• This appears related to a separate Coder symptom where sandbox bootstrap workspace verification fails on its first execute(), but this issue is the simpler upstream repro.

[linear]

AGENT-1467

[coderabbitai]

⚠️ Possible Duplicate Issue(s)

• Catalyst sandbox exec/job create intermittently returns 500 while still creating queued executions or pending jobs #1370

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