Stream: git-wasmtime

Topic: wasmtime / issue #11561 Panic instantiating table with ex...

Wasmtime GitHub notifications bot (Aug 28 2025 at 22:42):

alexcrichton opened issue #11561:

This input:

(module
  (table $t 10 exnref)
  (global $g exnref (ref.null exn))
  (elem (table $t) (i32.const 0) exnref (global.get $g))
)

fails with:

$ cargo run -- -Wexceptions,gc,function-references testcase0.wat
...
thread 'main' panicked at crates/wasmtime/src/runtime/vm/instance.rs:971:72:
called `Result::unwrap()` on an `Err` value: type mismatch: value does not match table element type

Caused by:
    type mismatch: expected (ref null exn), found (ref null none)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

cc @cfallin

Wasmtime GitHub notifications bot (Aug 28 2025 at 22:42):

alexcrichton added the fuzz-bug label to Issue #11561.

Wasmtime GitHub notifications bot (Aug 28 2025 at 22:42):

alexcrichton added the wasm-proposal:exceptions label to Issue #11561.

Wasmtime GitHub notifications bot (Aug 29 2025 at 03:21):

alexcrichton closed issue #11561:

This input:

(module
  (table $t 10 exnref)
  (global $g exnref (ref.null exn))
  (elem (table $t) (i32.const 0) exnref (global.get $g))
)

fails with:

$ cargo run -- -Wexceptions,gc,function-references testcase0.wat
...
thread 'main' panicked at crates/wasmtime/src/runtime/vm/instance.rs:971:72:
called `Result::unwrap()` on an `Err` value: type mismatch: value does not match table element type

Caused by:
    type mismatch: expected (ref null exn), found (ref null none)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

cc @cfallin

Last updated: Dec 06 2025 at 06:05 UTC