wasmtime-wasi only preopening the first and last directory set in WasiCtxBuilder

[justingaffney]

Test Case

Clone example repo here: https://github.com/justingaffney/wasmtime-preopen-bug

Steps to Reproduce

• Build component
  • cd component
  • cargo component build --release
• Run host
  • cd ..
  • cargo run

Expected Results

The following output:

Reading /a: Success
Reading /b: Success
Reading /c: Success
Reading /d: Success
Reading /e: Success

Actual Results

The following output:

Reading /a: Success
Reading /b: Failed. Error: Some(Custom { kind: Uncategorized, error: "failed to find a pre-opened file descriptor through which \"/b\" could be opened" })
Reading /c: Failed. Error: Some(Custom { kind: Uncategorized, error: "failed to find a pre-opened file descriptor through which \"/c\" could be opened" })
Reading /d: Failed. Error: Some(Custom { kind: Uncategorized, error: "failed to find a pre-opened file descriptor through which \"/d\" could be opened" })
Reading /e: Success

Versions and Environment

Wasmtime version or commit: 28.0.1, 29.0.0

Operating system: Windows 11

Architecture: x86_64

[justingaffney]

I just tried it on Ubuntu 24.04.1 and have the same issue

[alexcrichton]

Thanks for the report! This should be fixed in #10064. I'll note though that this is a bug in the "adapter" which will take a bit of time to propagate to toolchains. In the meantime working around this will be difficult as the adapter is pretty deep inside tooling and difficult to update-on-a-dime.