Compile Error: assertion left == right failed: Unexpected output from mysql_config: -L/usr/local/mysql/lib -lmysqlclient -lssl -lcrypto -lresolv

[prodbyola]

Setup

Versions

• **Rust:1.72
• **Diesel:2.2.0
• **Database:MySQL
• **Operating SystemMacOS 12

Feature Flags

• diesel: ["mysql", "chrono", "r2d2"]

Problem Description

I've been using diesel for awhile with no issue. Recently I started getting this compilation error and all efforts to troubleshoot have failed, including downgrading to previous versions. This is the error:

--- stderr
  thread 'main' panicked at /Users/prodbyola/.cargo/registry/src/index.crates.io-6f17d22bba15001f/mysqlclient-sys-0.3.1/build.rs:59:9:
  assertion `left == right` failed: Unexpected output from mysql_config: `-L/usr/local/mysql/lib -lmysqlclient -lssl -lcrypto -lresolv`
    left: 5
   right: 2
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

I also tried moving my project to Windows (WSL) to be sure it's not platform-specific issue. But I got very similar error. I'm not sure how to fix this please.

What are you trying to accomplish?

What is the expected output?

What is the actual output?

Are you seeing any additional errors?

Steps to reproduce

Checklist

• I have already looked over the issue tracker and the discussion forum for similar possible closed issues.

• This issue can be reproduced on Rust's stable channel. (Your issue will be
  closed if this is not the case)
• This issue can be reproduced without requiring a third party crate

[weiznich]

Thanks for reporting.
This is an issue in the mysqlclient-sys crate, not a diesel issue. The build script logic there expects a different output from the mysql_config tool.

You likely can workaround this by setting the MYSQLCLIENT_LIB_DIR environment variable to point to the right folder.