cargo编译musl报错openssl

背景

生产环境和编译环境的glibc版本不同出现来如下报错

/lib64/libc.so.6: version `GLIBC_x.xx' not found

所以需要使用cargo 跨平台编译x86_64-unknown-linux-musl，而后就报出来openssl相关的错误：

--- 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 = x86_64-unknown-linux-musl
openssl-sys = 0.9.48

原因

上文总结一句话：编译器没找到ssl的dev包，并给出来debian和red-hat的解决方法。但很可惜，我的编译环境是manjaro，没有libssl_dev类似的包

解决

对于debian/ubuntu就是

apt-get install libssl-dev

对于centos/fedora就是

yum install -y openssl-devel

对于Arch/manjaro，在确保安装openssl情况下

export OPENSSL_DIR=/usr

具体过程通过命令找到libssl.so文件路径(这里是/usr/lib/libsso.so)。编译时会连接OPENSSL_DIR/lib/libssl.so。因此这里的OPENSSL_DIR就是/usr了。