# error: the package `crate_name` requires rustc >= X.Y.Z, but the current rustc version is A.B.C

- **ID:** `rust/cargo-msrv-version-conflict`
- **Domain:** rust
- **Category:** install_error
- **Verification:** ai_generated
- **Fix Rate:** 90%

## Root Cause

A dependency or the package itself specifies a minimum supported Rust version (MSRV) higher than the currently installed Rust compiler version, causing a build failure.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| rustc 1.70.0 | active | — | — |
| rustc 1.71.0 | active | — | — |
| rustc 1.72.0 | active | — | — |
| cargo 1.70.0 | active | — | — |

## Workarounds

1. **Update Rust to the required version using `rustup`: `rustup update stable` to get the latest stable, or `rustup install X.Y.Z && rustup default X.Y.Z` for a specific version.** (95% success)
   ```
   Update Rust to the required version using `rustup`: `rustup update stable` to get the latest stable, or `rustup install X.Y.Z && rustup default X.Y.Z` for a specific version.
   ```
2. **If you cannot update Rust, find an older version of the dependency that supports your Rust version by specifying an exact version in `Cargo.toml`: `crate_name = "=1.2.3"` where `1.2.3` is known to work.** (85% success)
   ```
   If you cannot update Rust, find an older version of the dependency that supports your Rust version by specifying an exact version in `Cargo.toml`: `crate_name = "=1.2.3"` where `1.2.3` is known to work.
   ```
3. **Use `cargo +nightly build` to temporarily use a nightly toolchain if the MSRV requirement is for stable, but note nightly may have other issues; better to use the specific required version.** (75% success)
   ```
   Use `cargo +nightly build` to temporarily use a nightly toolchain if the MSRV requirement is for stable, but note nightly may have other issues; better to use the specific required version.
   ```

## Dead Ends

- **** — This only affects the local package's MSRV, not the dependency's MSRV; the error comes from the dependency's requirement, which is enforced by Cargo. (90% fail)
- **** — If all compatible versions of the dependency have the same or higher MSRV, `cargo update` won't resolve the issue; it may even pull a version with an even higher MSRV. (70% fail)
- **** — This is fragile, requires maintaining a fork, and may break if the dependency uses features only available in newer Rust versions. (80% fail)