debug-php-wasm-main-module
Installation
SKILL.md
Debugging PHP.wasm Main Module
Patterns for diagnosing and fixing crashes in the main PHP.wasm binary — Asyncify unwind/rewind failures, JSPI suspension errors, memory growth bugs, and runtime WASM traps.
Error Message Interpretation
Asyncify errors
| Error message | Likely cause |
|---|---|
RuntimeError: unreachable |
A function on the call stack is missing from ASYNCIFY_ONLY |
memory access out of bounds |
An opcode handler is missing — Asyncify corrupts the stack during rewind |
null function or signature mismatch |
Missing ASYNCIFY_ONLY function elsewhere on the stack — corrupted Asyncify state causes this to manifest in a different function than the one actually missing |
table index is out of bounds |
Missing opcode handler (variant of the above) |
Secondary errors (undefined variable, corrupted state) after any of these are red herrings caused by the corrupted Asyncify rewind.