Empty CARGO_MANIFEST_DIR env when running with dx

[photino]

Problem

Steps To Reproduce

Steps to reproduce the behavior:

• Gets the CARGO_MANIFEST_DIR
• When running the code with dx, it prints empty string.

if let Ok(s) = std::env::var("CARGO_MANIFEST_DIR") {
    tracing::info!("CARGO_MANIFEST_DIR: {}", s);
} else {
    tracing::info!("No CARGO_MANIFEST_DIR");
}

Expected behavior

The env should not be empty.

Screenshots

Environment:

• Dioxus version: 0.6.3
• Rust version: 1.85
• OS info: Windows
• App platform: Desktop

Questionnaire

I'm interested in fixing this myself but don't know where to start.

[photino]

From Environment variables Cargo sets for crates, it says

Note that if one of these values is not provided in the manifest, the corresponding environment variable is set to the empty string, "".

It means that dx serve does not run with cargo. How can we get the dir like CARGO_MANIFEST_DIR?

Perhaps we need a DIOXUS_MANIFEST_DIR.