BUG: Don't explicitly set the OSX_DEPLOYMENT_TARGET
Created by: blowekamp
Setting the OSX_DEPLOYMENT_TARGET implicitly controls which C++ standard library is used libstdc++ vs libc++. Mixing the two in binaries can result in unstable behavior.
We now implicitly configure the OSX_SYSROOT to the latest SDK, but require the user to explicitly set the OSX_DEPLOYMENT_TARGET to ensure compatibility with the build environment.
Co-authored-by: Hans Johnson hans-johnson@uiowa.edu