Fix Cargo Install Failure On Macbook M2 (rabbitmqadmin)

by Luna Greco 56 views

Hey guys! Ever run into a snag while trying to install Cargo on your Macbook M2? You're not alone! This guide breaks down a common issue encountered on the Darwin Kernel v24.6.0 arm64 platform, specifically errors during the rabbitmq_http_client compilation. Let's dive in and get this fixed!

Understanding the Issue: Cargo Installation Errors on Macbook M2

When you're trying to install rabbitmqadmin using Cargo, you might hit a wall with errors popping up during the compilation of the rabbitmq_http_client crate. These errors typically look like this:

error[E0658]: `let` expressions in this position are unstable
   --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/responses.rs:969:12
    |
969 |         if let Some(val) = self.arguments.get(argument)
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

error[E0658]: `let` expressions in this position are unstable
   --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/responses.rs:970:16
    |
970 |             && let Some(s) = val.as_str()
    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

error[E0658]: `let` expressions in this position are unstable
    --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/responses.rs:1285:12
     |
1285 |         if let Some(m) = &self.0
     |            ^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

error[E0658]: `let` expressions in this position are unstable
    --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/responses.rs:1286:16
     |
1286 |             && let Some(raw_val) = m.get(argument)
     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

error[E0658]: `let` expressions in this position are unstable
    --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/responses.rs:1287:16
     |
1287 |             && let Some(s) = raw_val.as_str()
     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

error[E0658]: `let` expressions in this position are unstable
  --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/transformers.rs:63:16
   |
63 |             if let Some(val) = qd.arguments.get(X_ARGUMENT_KEY_X_OVERFLOW)
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

error[E0658]: `let` expressions in this position are unstable
  --> /Users/user/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rabbitmq_http_client-0.40.0/src/transformers.rs:79:16
   |
79 |             if let Some(val) = p.definition.get(key)
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #53667 <https://github.com/rust-lang/rust/issues/53667> for more information

For more information about this error, try `rustc --explain E0658`.
error: could not compile `rabbitmq_http_client` (lib) due to 7 previous errors
warning: build failed, waiting for other jobs to finish...
error: failed to compile `rabbitmqadmin v2.7.2`, intermediate artifacts can be found at `/var/folders/39/7bbygjx54yx59jkbm33qfs1w0000gn/T/cargo-installwr46fS`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.

These errors, specifically the error[E0658]: 'let' expressions in this position are unstable, point to a compatibility issue with the Rust compiler and the rabbitmq_http_client crate version. The Rust compiler is flagging the use of let expressions within if conditions as unstable features. This means that the Rust version you're using might not fully support this syntax, or the crate you're trying to compile is using features that are still under development in Rust.

This issue is particularly common on Macbook M2 devices running Darwin Kernel versions like 24.6.0 due to the specific architecture (arm64) and the interaction with certain Rust versions and crate dependencies. Understanding this root cause is the first step in resolving the problem.

Why Does This Happen?

  1. Rust Unstable Features: The Rust language has features that are considered