Stream: git-wasmtime

Topic: wasmtime / issue #12158 wasip2/component panics when prof...

Wasmtime GitHub notifications bot (Dec 11 2025 at 20:15):

vavrusa opened issue #12158:

Test Case

At least any wasip2 program crashes when compiling and profiler is enabled in config. Here's an example. Similar to https://github.com/bytecodealliance/wasmtime/issues/8734

% git diff
diff --git a/examples/wasip2-async/main.rs b/examples/wasip2-async/main.rs
index db44473d5..e0a26bb5f 100644
--- a/examples/wasip2-async/main.rs
+++ b/examples/wasip2-async/main.rs
@@ -35,6 +35,7 @@ async fn main() -> Result<()> {
     // Construct the wasm engine with async support enabled.
     let mut config = Config::new();
     config.async_support(true);
+    config.profiler(wasmtime::ProfilingStrategy::PerfMap);
     let engine = Engine::new(&config)?;
     let mut linker = Linker::new(&engine);
     wasmtime_wasi::p2::add_to_linker_async(&mut linker)?;

Steps to Reproduce

% cmake examples/
% make
% cargo run --example wasip2-async
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.42s
     Running `target/debug/examples/wasip2-async`

thread 'main' (27706816) panicked at crates/wasmtime/src/runtime/instantiate.rs:179:17:
assertion `left == right` failed
  left: StaticModuleIndex(1)
 right: StaticModuleIndex(0)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Expected Results

Not panicking

Actual Results

Panics

Versions and Environment

Wasmtime version or commit: v39

Operating system: MacOS and Linux

Architecture: aarch64 and amd64

Extra Info

I upgraded from v22 to v39, not sure when it broke but is also broken on current main branch.

Wasmtime GitHub notifications bot (Dec 11 2025 at 20:15):

vavrusa added the bug label to Issue #12158.

Last updated: Dec 13 2025 at 19:03 UTC