shadowsocks-rust: windows 7 build failed

toolchain: nightly-x86_64-pc-windows-msvc (default) rustc 1.27.0-nightly (7360d6dd6 2018-04-15)

cargo build --release … error: failed to run custom build command for openssl-sys v0.9.28 process didn’t exit successfully: C:\Users\xxx\Documents\vscode\shadowsocks-rust\target\release\build\openssl-sys-58fb47c380c62ab0\build-script-build (exit code: 101) — stdout cargo:rerun-if-env-changed=X86_64_PC_WINDOWS_MSVC_OPENSSL_LIB_DIR cargo:rerun-if-env-changed=OPENSSL_LIB_DIR cargo:rerun-if-env-changed=X86_64_PC_WINDOWS_MSVC_OPENSSL_INCLUDE_DIR cargo:rerun-if-env-changed=OPENSSL_INCLUDE_DIR cargo:rerun-if-env-changed=X86_64_PC_WINDOWS_MSVC_OPENSSL_DIR cargo:rerun-if-env-changed=OPENSSL_DIR note: vcpkg did not find openssl as libcrypto and libssl : VcpkgNotFound(“No vcpkg.user.targets found. Set the VCPKG_ROOT environment variable or run 'vcpkg integrate install'”) note: vcpkg did not find openssl as ssleay32 and libeay32: VcpkgNotFound(“No vcpkg.user.targets found. Set the VCPKG_ROOT environment variable or run 'vcpkg integrate install'”)

— stderr thread ‘main’ panicked at ’

Could not find directory of OpenSSL installation, and this -sys crate cannot proceed without this knowledge. If OpenSSL is installed and this crate had trouble finding it, you can set the OPENSSL_DIR environment variable for the compilation process.

If you’re in a situation where you think the directory should be found automatically, please open a bug at https://github.com/sfackler/rust-openssl and include information about your system as well as this message.

$HOST = x86_64-pc-windows-msvc
$TARGET = x86_64-pc-windows-msvc
openssl-sys = 0.9.28

It looks like you’re compiling for MSVC but we couldn’t detect an OpenSSL installation. If there isn’t one installed then you can try the rust-openssl README for more information about how to download precompiled binaries of OpenSSL:

https://github.com/sfackler/rust-openssl#windows

', C:\Users\xxx.cargo\registry\src\github.com-1ecc6299db9ec823\openssl-sys-0.9.28\build.rs:213:5 note: Run with RUST_BACKTRACE=1 for a backtrace.

warning: build failed, waiting for other jobs to finish… error: build failed