wasmer run {url} interprets c:// file paths as URLs on Windows

[lt-gerjan]

Describe the bug

I get the following error:

>  wapm run cowsay
error: error fetching c:\Users\username\wapm_packages\syrusakbary/[email protected]\target/wasm32-wasi/release/cowsay.wasm: get_webc_bytes failed

> wasmer -V
wasmer 3.0.1

Steps to reproduce

Run above command on Windows

Expected behavior

Output from cowsay

Actual behavior

Error, see above

[fschutt]

I could reproduce this, it seems that this was a bug from the migration from wapm run to wasmer run: wapm run creates a file cowsay.cmd in ~/wapm_packages/.bin with the content:

@"wapm" run cowsay %*

When the command is executed, wasmer will be invoked with the path to the file, and for some reason it interprets the file path as a Url. This seems to only happen on Windows because Windows file paths start with C://, which gets parsed into a Url like http://. So it will try to fetch the file from the network and fail at that.

As a workaround wasmer run cowsay does work, even though there is some output that shouldn't happen.