Cargo dependency issue with openssl

[gumshoe2020]

So, I am trying to build a hyper server from Swagger using the Swagger codegen.

It builds the server stub successfully, but when I try to build it, I get an openSSL build error.

The server mustache files are 2 years old, and it is trying to pull an older version of openSSL than I have locally on my machine.

gumshoe2020/swagger-rust

Compiling quote v1.0.4
Compiling url v1.7.2
Compiling mime v0.2.6
error: failed to run custom build command for openssl v0.9.24

Caused by:
process didn't exit successfully: /Users/andrevan/Desktop/Andrew/Charter/IstioProjects/swagger-rust/target/debug/build/openssl-dfea6b48aa86ef68/build-script-build (exit code: 101)
--- stderr
thread 'main' panicked at 'Unable to detect OpenSSL version', /Users/andrevan/.cargo/registry/src/github.com-1ecc6299db9ec823/openssl-0.9.24/build.rs:16:14
note: run with RUST_BACKTRACE=1 environment variable to display a backtrace

There is a fix for the openSSL end of it here OpenSSL build issue on OS X
But what concerns me is the fact that I am using the carets to pull the latest version and it is still trying to get 0.9.24 of rust-openssl.

How do I get it to pull the latest version?

[kornel]

Run cargo install cargo-tree; cargo tree to see what is requesting openssl. Maybe some deeper dependency wants an old version.

Alternatively, delete Cargo.lock. I've seen a bug recently that made Cargo pick an old version for no good reason.

openssl crate isn't very clear about this, but it wants pkg-config installed as well. Make sure you have it, otherwise it won't find openssl even if openssl is installed.

[gumshoe2020]

Thanks, cargo tree is incredibly helpful.
The offender is in the old Swagger lib, which has probably not been updated in ages.