OpenSSL crate fails compilation on Mac OS X 10.11

Solution 1:

As of rust-openssl version 0.8, Homebrew-installed OpenSSL libraries will be automatically detected by the crate, there is no need to set extra environment variables.

If you need to support a version prior to that or choose to not use Homebrew, read on.

This is a known issue (also this and this), but not one that the crate can fix.

The quick solution is to install OpenSSL with Homebrew and then explicitly point to the directories where OpenSSL is found by setting the OPENSSL_INCLUDE_DIR and OPENSSL_LIB_DIR environment variables:

OPENSSL_INCLUDE_DIR=/usr/local/Cellar/openssl/1.0.2e/include \
OPENSSL_LIB_DIR=/usr/local/Cellar/openssl/1.0.2e/lib \
cargo build

If you've already done one cargo build, you will need to run cargo clean first to clear our some stale cached information.

If you don't want to set this for every shell you open, add it to your shell initialization files (like ~/.bash_profile). You can make it a bit less brittle by not hard-coding the version number:

export OPENSSL_INCLUDE_DIR=$(brew --prefix openssl)/include
export OPENSSL_LIB_DIR=$(brew --prefix openssl)/lib

If you don't want to use Homebrew, follow the same process but using the appropriate path to your copy of OpenSSL.

The longer reason is well described by andrewtj:

OpenSSL doesn't have a stable ABI so for compatibility purposes Apple have maintained a fork that's compatible with one of the earlier ABIs. They deprecated OpenSSL in 10.7 and finally dropped the headers in 10.11 to push OS X app developers toward bundling their own OpenSSL or using their frameworks. The dylibs have been left around so apps that haven't been updated don't break. You can still link against them but you're opening yourself up to odd compatibility issues by doing so (unless you grab the headers from an earlier OS X release).

Solution 2:

With Brew use like this:

brew install openssl
export OPENSSL_INCLUDE_DIR=`brew --prefix openssl`/include
export OPENSSL_LIB_DIR=`brew --prefix openssl`/lib
cargo clean
cargo build

Solution 3:

If you have homebrew's openssl installed just add the following to your Cargo.toml:

[target.x86_64-apple-darwin.openssl-sys]
rustc-link-search = [ "/usr/local/opt/openssl/lib" ]
rustc-link-lib = [ "ssl", "crypto" ]
include = [ "/usr/local/opt/openssl/include" ]

and then cargo clean && cargo build. No breaking OS X by introducing an incompatible openssl into the library load paths, and no forgetting to set/unset environment variables when you want to build (or polluting your shell env when not working on Rust stuff). All in all a much happier and less infuriating approach.

I can't add this answer to my own question where it belongs (because it depends on homebrew), because Shepmaster decided it should be closed but I'll answer here and link to that question.

Solution 4:

https://stackoverflow.com/a/39380733/1317564's answer for MacPorts:

sudo port install openssl
export OPENSSL_INCLUDE_DIR=/opt/local/include
export OPENSSL_LIB_DIR=/opt/local/lib
cargo clean
cargo build