Understanding Rust Error E0455

Introduction to Rust Error E0455

Rust Error E0455 occurs when a target-specific linking kind is used on an unsupported platform. For example, kind=framework is exclusive to macOS, and kind=raw-dylib is only supported on Windows-like platforms.

Error Example

#[link(name = "FooCoreServices", kind = "framework")] extern "C" {}
// OS used to compile is Linux for example

In this code example, the error E0455 arises because the kind=framework attribute is being used on a non-macOS platform.

Solving Rust Error E0455

To fix this error, conditional compilation can be utilized, which allows specifying the linking kind based on the target platform. The following example demonstrates how to use conditional compilation to avoid error E0455:

fn main() {
#[cfg_attr(target="macos", link(name = "FooCoreServices", kind = "framework"))]
extern "C" {}

In this revised code, the #[cfg_attr] attribute is used to conditionally apply the kind=framework attribute only when targeting the macOS platform. As a result, error E0455 will be avoided.

General Tips for Avoiding E0455

1. Ensure that you are using the appropriate linking kind for each platform. Remember that kind=framework is specific to macOS, and kind=raw-dylib is exclusive to Windows-like platforms.

2. Use conditional compilation with #[cfg_attr] to apply linking kinds only when targeting specific platforms.

3. Always verify your platform requirements and target the correct platforms while linking libraries.

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