Another Crab's Treasure — PPSA20423

[JJenkx]

Tested Another Crab's Treasure — PPSA20423 on Linux / Ryzen 9 7950X / Radeon RX 6650 XT, RADV Mesa 26.2.4. This is a short native bring-up check, not a full playability or performance report.

Result

Literal main d5c956a10087914b52922fd3ece6439ccbb3e741 stops after the opening video with exit 134:

[gpu] driver failure: AGC graphics: a CPU read of 0x2d5a00000+0x814000 overlaps multisampled color target 0x2d5a10000+0x800000 (2 samples), whose samples are only on the host: guest access to it is not implemented

The captured stack reaches RequireNoMultisampleTarget through GuestMemory::Read, acquireMirror, AcquireRegistered, prepareAddressBindings, and DrawPipeline. The read is triggered while uploading a buffer mirror overlapping the native MSAA target.

A local composition of that main with #6995, head 7b090b67d0afdf65a84c91be771635691b53f7f0, reaches the Loan Shark introduction and the first controllable beach scene. Credit to Amoenus / Romans Pokrovskis and the prerequisite authors for the implementation. The local merge is f301503ced91433b6e33a10a67c789620a4350c9; no additional driver implementation was added.

The movement follow-up injected left-stick right at 231s and forward at 251s. Screenshots at 225s, 245s and 270s show the crab move from beside Loan Shark along the beach and then beside the rock wall. It closed normally at 320s, exited 0 at 322s, and left no native process; the temporary kernel setting was restored. A separate 322s diagnostic run also reached the animated gameplay scene and exited 0.

Required open work

• feat(agc): publish native color before guest memory reads #6995, including its declared feat(agc): publish completed native color snapshots #6989 prerequisites, is the tested dependency stack for this MSAA guest-read stop. This report does not isolate the benefit of every prerequisite.
• These tests pin main to d5c956a100; upstream has advanced since then. They are not a claim about every subsequent main revision.
• Right-stick camera response was not confirmed by the final screenshots. Audio, later areas, save/load and long sessions remain untested. No FPS gain or complete graphical correctness is claimed.

Earlier stationary intro screenshots initially looked like a stall. Later diagnostic and movement runs disproved a persistent intro freeze; the initial stationary run is not evidence of a deadlock.

Validation and evidence

The same ten selected baseline MSAA/guest-access tests pass on both source pins; the candidate also passes seven additional fixtures (main 10/10, composition 17/17). Vulkan was required, application shader cache disabled and Khronos validation requested; the logs contain no missing-requested-layer warning, skipped tests or VUID- diagnostics. These focused tests do not establish whole-suite correctness.

Evidence archive: native reports/logs, focused logs, throw stack, input harness, screenshots and SHA-256 manifest. Reports include actual mapped driver paths/revision and input timing. The local input harness needs its local paths adapted for another machine.

Before movement (225s):

After first movement (245s):

AI-assisted testing and report: yes, Codex.