Context

The daemon project uses <InvariantGlobalization>true</InvariantGlobalization> to reduce binary size (~28MB savings by stripping ICU culture data). This is incompatible with Discord.Net.

Problem

Discord's Guild object has a required preferred_locale field (always present, defaults to en-US). Discord.Net unconditionally maps this to a .NET CultureInfo in SocketGuild.Update:

new CultureInfo(PreferredLocale)  // throws in invariant mode

When InvariantGlobalization=true, the runtime only supports CultureInfo.InvariantCulture. Any real locale like en-US throws CultureNotFoundException, which prevents guild data from loading. Without guild data, the channel cache is empty and all incoming messages are dropped as "Unknown Channel."

This is a known open issue in Discord.Net (#2704) with no library-side fix. There is no Discord.Net configuration to skip the CultureInfo construction — it is hardcoded.

Resolution

Disable InvariantGlobalization in src/Netclaw.Daemon/Netclaw.Daemon.csproj. This adds ~28MB to the self-contained binary (ICU data) but is required for Discord channel support.

The CLI (Netclaw.Cli) retains InvariantGlobalization=true since it does not load Discord.Net.

Why not alternative approaches?

• PredefinedCulturesOnly: Still requires ICU data bundled; no meaningful size savings over full globalization.
• Patching Discord.Net: The CultureInfo construction is in a hot path (SocketGuild.Update) called on every guild event. A fork would be a maintenance burden, and the upstream issue has been open since 2023 with no resolution.
• Runtime culture injection: Not possible in invariant mode — the runtime rejects all non-invariant cultures regardless of how they're constructed.

For future contributors

If you're optimizing binary size and consider re-enabling InvariantGlobalization, be aware this will break Discord channel support entirely. The daemon will connect to Discord's gateway but silently drop all messages because guild/channel data fails to load. The error appears as:

[ERR] Gateway: Error handling Dispatch (GUILD_AVAILABLE)
System.Globalization.CultureNotFoundException: Only the invariant culture is supported in globalization-invariant mode.
en-US is an invalid culture identifier.

Followed by:

[WRN] Gateway: Unknown Channel (MESSAGE_CREATE Channel=...)

This setting cannot be changed until Discord.Net resolves #2704.