Stream: wasmtime

Topic: ✔ pulley32 on x86_64-unknown-linux-gnu

view this post on Zulip Julien Cretin (ia0) (Aug 28 2025 at 12:16):

I've just used unimplemented!() and it seems those functions are not called.

view this post on Zulip Notification Bot (Aug 28 2025 at 12:16):

Julien Cretin (ia0) has marked this topic as resolved.

view this post on Zulip Alex Crichton (Aug 28 2025 at 15:54):

I'm wondering if there's a way to avoid doing that

In theory this should bottom out with crate features for Wasmtime, where if neither custom-virtual-memory nor custom-native-signals is enabled it shouldn't require anything more thatn wasmtime_tls_*

view this post on Zulip Alex Crichton (Aug 28 2025 at 15:55):

This might be a bug in Wasmtime though where we're detecting linux for i686-unknown-linux-gnu and assuming there's virtual memory when no_std is otherwise active? Would you be able to post a reproduction and/or work-in-progress which requires the symbols that it shouldn't?

view this post on Zulip Julien Cretin (ia0) (Aug 29 2025 at 08:10):

In theory this should bottom out with crate features for Wasmtime, where if neither custom-virtual-memory nor custom-native-signals is enabled it shouldn't require anything more thatn wasmtime_tls_*

I'm using default-features = false and features = ["async", "runtime"].

assuming there's virtual memory when no_std is otherwise active?

Mmm... the library that depends on Wasmtime is no-std, but the final binary isn't.

Would you be able to post a reproduction

You can clone https://github.com/ia0/wasefire.git, checkout the branch tmp/pulley-i686-linux, move to the crates/runner-host directory, and run:

PKG_CONFIG_SYSROOT_DIR=/usr/lib/i386-linux-gnu/pkgconfig cargo build --release --target=i686-unknown-linux-gnu --features=debug,pulley

You can uncomment the lines commented in the last commit to fix the issue. Those are in the crates/scheduler/src/applet/store/pulley.rs file.

You might need some dependencies like libudev-dev, libssl-dev, libssl-dev:i386, gcc-multilib, and linux-tools-common (or usbip).

GitHub - ia0/wasefire: Secure firmware framework focusing on developer experience
Secure firmware framework focusing on developer experience - ia0/wasefire

view this post on Zulip Alex Crichton (Aug 29 2025 at 14:43):

Thanks! I was able to confirm that https://github.com/bytecodealliance/wasmtime/pull/11568 should make this go away and work as expected

Fix no_std builds on supported targets by alexcrichton · Pull Request #11568 · bytecodealliance/wasmtime
This commit fixes a conditional in Wasmtime's build script from accidentally considering Unix and Windows targets as being a supported OS with all the bells and whistles. This is only true if t...

view this post on Zulip Julien Cretin (ia0) (Aug 29 2025 at 15:02):

Cool, thanks a lot!

Last updated: Dec 06 2025 at 06:05 UTC