Question

我在amd64 Debian机器上，我正在尝试构建一个x86_64-unknown-linux-musl可执行文件。我在Cargo.toml中有这个：

[dependencies]
curl = "0.4"

当我跑cargo build --target=x86_64-unknown-linux-musl时，我明白了这样：

error: failed to run custom build command for `libz-sys v1.0.10`
process didn't exit successfully: `/tmp/foo/target/debug/build/libz-sys-c20da5f29c41e515/build-script-build` (exit code: 101)
--- stdout
OPT_LEVEL = Some("0")
PROFILE = Some("debug")
TARGET = Some("x86_64-unknown-linux-musl")
debug=true opt-level=0
HOST = Some("x86_64-unknown-linux-gnu")
TARGET = Some("x86_64-unknown-linux-musl")
TARGET = Some("x86_64-unknown-linux-musl")
HOST = Some("x86_64-unknown-linux-gnu")
CC_x86_64-unknown-linux-musl = None
CC_x86_64_unknown_linux_musl = None
TARGET_CC = None
CC = None
HOST = Some("x86_64-unknown-linux-gnu")
CROSS_COMPILE = None
TARGET = Some("x86_64-unknown-linux-musl")
HOST = Some("x86_64-unknown-linux-gnu")
CFLAGS_x86_64-unknown-linux-musl = None
CFLAGS_x86_64_unknown_linux_musl = None
TARGET_CFLAGS = None
CFLAGS = None
running: "./configure" "--prefix=/tmp/foo/target/x86_64-unknown-linux-musl/debug/build/libz-sys-e109627694e9981e/out"
Compiler error reporting is too harsh for ./configure (perhaps remove -Werror).
** ./configure aborting.

--- stderr
thread 'main' panicked at 'failed to run successfully: exit code: 1', /home/tshepang/.cargo/registry/src/github.com-1ecc6299db9ec823/libz-sys-1.0.10/build.rs:189

当我重新运行时：

error: failed to run custom build command for `openssl-sys v0.9.6`
process didn't exit successfully: `/tmp/foo/target/debug/build/openssl-sys-ac9c042b062dad1d/build-script-build` (exit code: 101)
--- 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-unknown-linux-gnu
    $TARGET = x86_64-unknown-linux-musl
    openssl-sys = 0.9.6

当我本地构建时，一切正常，即cargo build --target=x86_64-unknown-linux-gnu。

搜索一下，我了解了一个环境变量PKG_CONFIG_ALLOW_CROSS：

PKG_CONFIG_ALLOW_CROSS=true cargo build --target=x86_64-unknown-linux-musl

在这样做的过程中，我还发现我错过了Debian软件包命名为 libcurl4-openssl-dev 。

正在运行ldd target/target/x86_64-unknown-linux-musl/debug/foo 表明可执行文件是动态链接的，然后搜索此外，我了解了另一个环境变量， PKG_CONFIG_ALL_STATIC：

PKG_CONFIG_ALL_STATIC=true PKG_CONFIG_ALLOW_CROSS=true cargo build --target=x86_64-unknown-linux-musl

这揭示了一大堆失踪的deps，所有这些（幸运的是）有Debian依赖。但安装所有这些并没有帮助，因为，最后，我仍然坐着一个没有的可执行文件静态联系。

Answer 1

我放弃并最终使用cross：

cargo install cross
cross build --target=x86_64-unknown-linux-musl

这太简单了，你会在target/x86_64-unknown-linux-musl/debug找到可执行文件。

Answer 2

curl箱子（直接或间接）依赖于两个箱子libz-sys和openssl-sys。一个名字以＆＃34; -sys＆＃34;结尾的箱子。通常是一组FFI（外部函数接口）绑定到本机C库。

建立这样一个＆＃34; -sys＆＃34; crate需要链接到本机库。如果您的目标是x86_64-unknown-linux-musl，那么您必须链接到针对musl构建的本机库，而不是glic。但是，您在发行版的存储库中找到的大多数软件包都提供了针对glibc构建的库。

解决方案是自己构建所需的库，链接到musl而不是glibc。

我无法访问Debian安装，但在Ubuntu 16.04上，这对于OpenSSL来说是这样的：

# this package provides the "musl-gcc" wrapper
apt-get install musl-tools 
# you will also need these, if they are not installed yet
apt-get install pkg-config xutils-dev build-essential

# Download and build OpenSSL against musl
VERS=1.0.2j
export CC=musl-gcc
export MUSL_PREFIX=/usr/local/musl
export C_INCLUDE_PATH="$MUSL_PREFIX/include/"
curl -O https://www.openssl.org/source/openssl-$VERS.tar.gz
tar xvzf openssl-$VERS.tar.gz
cd openssl-$VERS

./config --prefix "$MUSL_PREFIX"
make depend
make
sudo make install

export OPENSSL_DIR=/usr/local/musl/
export OPENSSL_STATIC=1

一旦你有一个相同的libz（我还没有尝试构建它），你应该能够建立你的箱子：

 cargo build --target=x86_64-unknown-linux-musl

，生成的二进制文件将位于target/x86_64-unknown-linux-musl/debug/<binary_name>

中

cross工具基本上可以做到这一点，但是在Docker容器中，以保持主机清洁。

此版本生成的二进制文件应该是静态链接的，甚至不依赖于glibc。这也意味着它会更大*并且如果在其中一个中发现安全问题，您将需要自己升级任何依赖项（尤其是OpenSSL）。

*您可能希望在已发布的二进制文件上使用strip。

如何为x86_64-unknown-linux-musl构建依赖于curl的可执行文件

2 个答案: