fix(warp): correct IPv6 address removal sed rule for IPv4-only VPS

[EricPrometheus]

Problem

On IPv4-only VPS (no IPv6 address, net.ipv6.conf.all.disable_ipv6 = 1), wg-quick@warp fails to start with:

[#] ip -6 address add 2606:4700:110:...:/128 dev warp
RTNETLINK answers: Permission denied
[#] ip link delete dev warp

The WARP tunnel becomes completely non-functional.

Root Cause

other/warp/wireguard/run.sh.j2 line 43 has a sed rule intended to strip IPv6 addresses when the system doesn't support IPv6:

# Old (broken)
sed -i '/Address = [0-9a-fA-F:]\{4,\}/s/^/# /' wgcf-profile.conf

However, wgcf generate produces Address lines with both IPv4 and IPv6 on the same line:

Address = 172.16.0.2/32, 2606:4700:110:8961:16c9:4520:593:6a9e/128

The old sed rule tries to match lines starting with IPv6 hex patterns, but since the line starts with 172.16.0.2, it doesn't match. The IPv6 address remains, wg-quick attempts ip -6 address add, and the kernel rejects it, causing the entire interface to be torn down.

Fix

Replace the sed rule to strip , <ipv6>/<prefix> from the Address line directly:

# New
sed -i 's/, [0-9a-fA-F:]*\/[0-9]*//' wgcf-profile.conf

Result:

# Before:
Address = 172.16.0.2/32, 2606:4700:110:8961:16c9:4520:593:6a9e/128

# After:
Address = 172.16.0.2/32

Testing

• Verified on RackNerd IPv4-only VPS (Ubuntu 22.04, kernel 5.15.0-46)
• WARP tunnel starts successfully after applying the fix
• curl --interface warp https://cloudflare.com/cdn-cgi/trace confirms warp=on

File Changed

• other/warp/wireguard/run.sh.j2 — 1 line changed