Rust cargo build compilation failure

Playbook ID: cargo-compile-error Category: build Severity: high Tags: rust, cargo, compile, build, rustc, borrow-checker

What this failure means

The Rust compiler rejected the crate with one or more hard errors — type mismatches, borrow checker violations, unresolved imports, or missing trait implementations. The binary cannot be produced until all errors are resolved.

Common log signals

error[E
error: could not compile
aborting due to previous error
aborting due to
undefined reference to
multiple definition of

Diagnosis

rustc emits structured errors in the form error[EXXXX]: <description> followed by source locations. Every error is deterministic and must be resolved before the build can succeed.

Common error classes:

• E0308 — mismatched types: a value of one type is used where a different type is expected. Check function signatures and generic bounds.
• E0382 — borrow of moved value / E0502 — conflicting borrows: the borrow checker rejected unsafe aliasing or use-after-move. Review ownership and lifetime annotations.
• E0412 / E0433 — unresolved name or module: a type, function, or crate is referenced that is not in scope. Add the correct use statement or add the crate to Cargo.toml.
• E0277 — trait not implemented: a concrete type is used where a trait bound is required but the type does not implement the trait. Implement the trait or use a type adapter.
• E0599 — method not found: the method does not exist for this type, or a required feature flag is not enabled.

The compiler always names the exact file, line, and column. Start there.

Fix steps

1. Run cargo build locally to reproduce the exact error output:

   cargo build 2>&1 | head -60
   

2. Read the first error and its suggestion. rustc often suggests the exact fix (e.g., help: consider borrowing here: &val).

3. For E0308 type mismatch: check the types on both sides of the assignment or call and add an explicit conversion or change the type.

4. For E0382/E0502 borrow errors: restructure to avoid overlapping borrows, use .clone() where ownership transfer is undesirable, or annotate lifetimes explicitly.

5. For E0412/E0433 unresolved path: verify the crate is listed in Cargo.toml and the use path matches the module tree:

   cargo tree | grep <crate-name>
   

6. For E0277 trait not implemented: implement the missing trait for your type, or add a #[derive(...)] macro if the trait supports it.

7. Run cargo check after each fix for fast feedback without producing a binary:

   cargo check
   

Validation

• cargo build exits zero with no error[E lines in output.
• cargo check exits zero.
• Confirm the CI build step exits zero.

Likely files to inspect

• **/*.rs
• Cargo.toml
• Cargo.lock
• rust-toolchain.toml
• rust-toolchain

Run Faultline

faultline analyze build.log
faultline explain cargo-compile-error
faultline workflow build.log --json --mode agent

Search phrases this page answers

• Rust cargo build compilation failure
• Build: rust cargo build compilation failure
• aborting due to previous error
• GitHub Actions rust cargo build compilation failure
• faultline explain cargo-compile-error
• Rust rust cargo build compilation failure

---

Generated from playbooks/bundled/log/build/cargo-compile-error.yaml. Do not edit directly — run make docs-generate.