rust-openssl: Cross compilation issues with prebuilt 'openssl' libs

[vithalsm]

Hi,
Here is my scenario:
openssl-3.x - cross crompiled as 'conan' package and published to our internal conan registry.
Application:
. Wants to use 'rust-openssl' by setting 'dependency' to openssl and openssl-sys (as explained in the README).
. Install pre-built cross compiled openssl-libs via 'build-dependencies' and build.rs. Build script build.rs uses 'conan2-rs' to run 'conan commands' to pull the dependencies (openssl system libs in this case).

However, this method doesn't work, as 'dependencies' are executed prior to 'build-dependencies'.
Hence 'openssl-sys' fails as build script runs later.

So, in such cases, is there any other alternatives?
If there are ways to achieve the same as described above please help with the info.

=====================================================
[dependencies]
openssl-sys = "0.9"
openssl = "0.10"

[build-dependencies]
conan2 = {version = "0.1.1"}
bindgen= {version = "0.69.4"}

build.rs ==>
...
...
use conan2::ConanInstall;
ConanInstall::new()
.profile(&conan_profile)
.build("missing")
.run()
.parse()
.emit();
...
...

[sfackler]

You would need to orchestrate conan outside of cargo.

[vithalsm]

Thanks @sfackler for the response.
Could you please elaborate on "orchestrate conan outside of cargo"?

[sfackler]

If you want to use Conan, you will need to run conan install with the proper generators, etc, and then call cargo build with the environment set up appropriately to point to the conan-installed openssl.

[vithalsm]

Ok. Thought about same, but wasn't sure how easy/difficult it would be to export the paths dynamically.
Same for using sub-crates within a workspace, wherein, using the first crate to do conan job via its build script and second using the stuffs.