为 ARM 编译时，Openssl 无法编译，否则工作正常

Question

所以最近我一直在为 ARM 编译一个 rust 项目。它可以完美地为 x86 编译，但是当我切换到 ARM 目标时，它找不到 Openssl 安装，我安装了 pkg-config 并且可以正常工作，所以它不是那个错误。不确定如何成功设置 OPENSSL_DIR 变量或自己在哪里找到安装。错误完全粘贴在下面

error: failed to run custom build command for `openssl-sys v0.9.61`

Caused by:
  process didn't exit successfully: `/home/bob/yagna/blueberry/debug/build/openssl-sys-aae22c7790b14724/build-script-main` (exit code: 101)
  --- stdout
  cargo:rustc-cfg=const_fn
  cargo:rerun-if-env-changed=ARMV7_UNKNOWN_LINUX_GNUEABIHF_OPENSSL_LIB_DIR
  ARMV7_UNKNOWN_LINUX_GNUEABIHF_OPENSSL_LIB_DIR unset
  cargo:rerun-if-env-changed=OPENSSL_LIB_DIR
  OPENSSL_LIB_DIR unset
  cargo:rerun-if-env-changed=ARMV7_UNKNOWN_LINUX_GNUEABIHF_OPENSSL_INCLUDE_DIR
  ARMV7_UNKNOWN_LINUX_GNUEABIHF_OPENSSL_INCLUDE_DIR unset
  cargo:rerun-if-env-changed=OPENSSL_INCLUDE_DIR
  OPENSSL_INCLUDE_DIR unset
  cargo:rerun-if-env-changed=ARMV7_UNKNOWN_LINUX_GNUEABIHF_OPENSSL_DIR
  ARMV7_UNKNOWN_LINUX_GNUEABIHF_OPENSSL_DIR unset
  cargo:rerun-if-env-changed=OPENSSL_DIR
  OPENSSL_DIR unset
  cargo:rerun-if-env-changed=OPENSSL_NO_PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG_ALLOW_CROSS_armv7-unknown-linux-gnueabihf
  cargo:rerun-if-env-changed=PKG_CONFIG_ALLOW_CROSS_armv7_unknown_linux_gnueabihf
  cargo:rerun-if-env-changed=TARGET_PKG_CONFIG_ALLOW_CROSS
  cargo:rerun-if-env-changed=PKG_CONFIG_ALLOW_CROSS
  cargo:rerun-if-env-changed=PKG_CONFIG_armv7-unknown-linux-gnueabihf
  cargo:rerun-if-env-changed=PKG_CONFIG_armv7_unknown_linux_gnueabihf
  cargo:rerun-if-env-changed=TARGET_PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_armv7-unknown-linux-gnueabihf
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR_armv7_unknown_linux_gnueabihf
  cargo:rerun-if-env-changed=TARGET_PKG_CONFIG_SYSROOT_DIR
  cargo:rerun-if-env-changed=PKG_CONFIG_SYSROOT_DIR
  run pkg_config fail: "pkg-config has not been configured to support cross-compilation.\n\n                Install a sysroot for the target platform and configure it via\n                PKG_CONFIG_SYSROOT_DIR and PKG_CONFIG_PATH, or install a\n                cross-compiling wrapper for pkg-config and set it via\n                PKG_CONFIG environment variable."

  --- 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.

  Make sure you also have the development packages of openssl installed.
  For example, `libssl-dev` on Ubuntu or `openssl-devel` on Fedora.

  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-unknown-linux-gnu
  $TARGET = armv7-unknown-linux-gnueabihf
  openssl-sys = 0.9.61

  ', /home/bob/.cargo/registry/src/github.com-1ecc6299db9ec823/openssl-sys-0.9.61/build/find_normal.rs:174:5
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

.cargo 配置文件也如下

[build]
target-dir="/home/bob/yagna/blueberry"
target="armv7-unknown-linux-gnueabihf"
linker = "arm-linux-gnueabihf-gcc"
[target.armv7-unknown-linux-gnueabihf]
linker = "arm-linux-gnueabihf-gcc"

不知如何是好，这个 ubuntu，我安装了 libssl-dev 并且是最新的，使用 rustup 和 sudo apt get 添加和安装目标。不知道如何解决这个问题

Answer 1

如果您使用 OpenSSL 为 armhf 编译某些东西，那么您需要为该架构安装 libssl-dev 软件包。这将涉及通过dpkg --add-architecture armhf 为其设置dpkg，然后执行apt-get update 和apt-get install libssl-dev:armhf。

请注意，一次安装多个版本的libssl-dev 可能是不可能的，并且以一种最终不会删除大量软件包的方式解决依赖关系可能会很棘手。 Debian 风格的多架构非常强大，但有时可能有点繁琐。

您绝对不应该供应 OpenSSL，因为它经常带有安全更新。同样，静态链接 OpenSSL 也是一个坏主意。如果你做供应商或静态链接它，除非你非常小心地保持它是最新的，否则你的代码将包含安全漏洞。