fix(ai): work around httpx NO_PROXY IPv6 CIDR crash

[lennondotw]

Problem

OrbStack / Docker Desktop automatically injects proxy environment variables into containers:

NO_PROXY=localhost,127.0.0.0/8,::1/128

httpx <= 0.28.1's get_environment_proxies() wraps IPv6 CIDR entries from NO_PROXY inside brackets including the CIDR mask (e.g. all://[::1/128]), causing the URL parser to misinterpret /128 as a port and throw Invalid port: ':1'.

This crashes AsyncOpenAI client initialization, making AI analysis completely unavailable.

Root Cause

In httpx _utils.get_environment_proxies():

elif is_ipv6_hostname(hostname):           # "::1/128" -> True
    mounts[f"all://[{hostname}]"] = None   # -> "all://[::1/128]"

is_ipv6_hostname correctly identifies IPv6 via split("/")[0], but the URL construction includes the CIDR mask inside brackets. URLPattern then parses [::1/128] and treats /128] as part of the authority, ultimately failing on int(":1").

Upstream fix PR (encode/httpx#3741) has passing CI but remains unmerged. httpx has not released for over 16 months.

Fix

Call _sanitize_no_proxy_env() before creating AsyncOpenAI in AIClient._initialize_client. This strips CIDR prefix lengths from IPv6 entries in NO_PROXY / no_proxy (e.g. ::1/128 -> ::1).

• IPv4 CIDR entries (e.g. 10.0.0.0/8) are preserved
• No functional loss: httpx 0.28.1 doesn't support CIDR range matching anyway
• Once httpx merges the upstream fix, this workaround becomes a harmless no-op

Tests

5 new unit tests covering: IPv6 CIDR stripping, case variants (NO_PROXY / no_proxy), IPv4 CIDR preservation, missing env vars, and both keys present simultaneously.

Verified in container: AIClient initializes successfully with NO_PROXY=localhost,127.0.0.0/8,::1/128.

[gemini-code-assist]

Code Review

This pull request introduces a _sanitize_no_proxy_env utility to strip CIDR prefixes from IPv6 entries in the NO_PROXY environment variables, addressing a known issue in httpx. It also includes comprehensive unit tests for this logic. Feedback suggests optimizing the IPv6 detection logic to avoid unnecessary exception handling for IPv4 addresses and cleaning up unused variables.

[gemini-code-assist]

Optimization: Adding a check for : before attempting to parse the host as an IPv6 address can avoid the overhead of the try/except block for IPv4 CIDRs (e.g., 127.0.0.0/8) and other non-IPv6 entries in NO_PROXY. Additionally, the prefix variable is unused and can be replaced with _ to follow Python conventions.

Suggested change

	if "/" in part:
	host, _, prefix = part.partition("/")
	try:
	ipaddress.IPv6Address(host)
	cleaned.append(host)
	changed = True
	continue
	except ValueError:
	pass
	cleaned.append(part)
	if "/" in part and ":" in part:
	host, _, _ = part.partition("/")
	try:
	ipaddress.IPv6Address(host)
	cleaned.append(host)
	changed = True
	continue
	except ValueError:
	pass
	cleaned.append(part)

[dingyufei615]

thanks bro