LuckPerms compatibility issue

[JayPeaSize]

Currently when using LuckPerms the following error is displayed:
[lp] permissions data for your user was not loaded during the pre-login

I believe the cause of this is that the pre-login UUID is not the proper UUID yet, but when they go to fully join it has changed by then.

[adde0109]

Arclight, Mohist or Magma?

[JayPeaSize]

Currently just using 1.16.5 SpongeForge. Would Arclight be better in this case? Bit new to 1.16.5 for forge. Been stuck in 1.12.2 because of pixelmon

[infered5]

Can confirm this also happens with Mohist 1.16.5. Every UUID I see in console is my online-mode (all servers are online with velocity and proxy-compatible-forge on servers + ambassador on velocity host.)

[17:02:40 WARN]: [LuckPerms] User 8a963d9d-cb13-472c-99d9-46c6b9097b8e - infered5 doesn't have data pre-loaded, they have never been processed during pre-login in this session. - denying login.

[unilock]

FabricProxy-Lite works around this with its "hackEarlySend" config option.

LuckPerms need enable hackEarlySend in config.

Because Fabric-API can't send packet before QUERY_START event, so player info(UUID) will not ready at QUERY_START event.

Enable hackEarlySend will use mixin for early send packet to velocity.

(relevant mixin)

[samuelh2005]

Open Parties and Claims have a similar issue, when joining the player's UUID becomes their offline mode UUID rather then their real UUID. Then without an error, the player get kicked.

I agree with the need for the hackEarlySend to be added into PCF.

[samuelh2005]

Using the Sinytra Connector mod and Fabric Proxy Light on a Forge server and having hackEarlySend enabled everything works as expected.

[p0t4t0sandwich]

Narrowed things down (accidentally while refactoring). Technically speaking, PCF already implements an equivalent to hackEarlySend, since PCF sends a query packet even earlier than FabricProxyLite does with hackEarlySend enabled (at least as far as I can tell).
The issue seems to arise from PCF's mixin placement in the ServerLoginPacketListenerImpl#handleHello method.
Tested with LuckPerms on a few Forge versions and things seem promising so far, still more testing to do before it's ready for a release though.

[p0t4t0sandwich]

Dug a bit deeper, and the issue that plagued modern versions was a bit different to the issue with LuckPerms on SpongeForge 1.16.5.
Normally this wouldn't be an issue, but SF 1.16.5's modern forwarding doesn't seem work, so PCF's and SF's mixins are running simultaneously, preventing a pre-pre-login event from firing, which then borks LP.
Work-shopping a solution via MixinSquared to try and re-order things somewhat to repair compat, so we'll see how that goes.