Unable to cross compile ubuntu -> mipsel-unknown-linux-musl

[kolapapa]

$HOST = x86_64-unknown-linux-gnu
$TARGET = mipsel-unknown-linux-musl
openssl-sys = 0.9.49

// error
$ cargo build --target=mipsel-unknown-linux-musl --release

error: failed to run custom build command for `openssl-sys v0.9.49`

Caused by:
  process didn't exit successfully: `/root/edge-agent/target/release/build/openssl-sys-e2a022d0d499c81d/build-script-main` (exit code: 101)
--- stdout
cargo:rustc-cfg=const_fn
cargo:rerun-if-env-changed=MIPSEL_UNKNOWN_LINUX_MUSL_OPENSSL_LIB_DIR
MIPSEL_UNKNOWN_LINUX_MUSL_OPENSSL_LIB_DIR unset
cargo:rerun-if-env-changed=OPENSSL_LIB_DIR
OPENSSL_LIB_DIR unset
cargo:rerun-if-env-changed=MIPSEL_UNKNOWN_LINUX_MUSL_OPENSSL_INCLUDE_DIR
MIPSEL_UNKNOWN_LINUX_MUSL_OPENSSL_INCLUDE_DIR unset
cargo:rerun-if-env-changed=OPENSSL_INCLUDE_DIR
OPENSSL_INCLUDE_DIR unset
cargo:rerun-if-env-changed=MIPSEL_UNKNOWN_LINUX_MUSL_OPENSSL_DIR
MIPSEL_UNKNOWN_LINUX_MUSL_OPENSSL_DIR unset
cargo:rerun-if-env-changed=OPENSSL_DIR
OPENSSL_DIR unset
run pkg_config fail: "Cross compilation detected. Use PKG_CONFIG_ALLOW_CROSS=1 to override"

--- 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 = mipsel-unknown-linux-musl
openssl-sys = 0.9.49

', /root/.cargo/registry/src/mirrors.ustc.edu.cn-61ef6e0cd06fb9b8/openssl-sys-0.9.49/build/find_normal.rs:150:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.

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

// success
$ cargo build 

[sfackler]

If you're cross compiling, you need to point the library to a copy of OpenSSL compiled for MUSL. Alternatively, you can enable the vendored Cargo feature to have openssl-sys compile it for you.

[kolapapa]

Thanks~ I got it~

[Nokel81]

I have enabled the vendored cargo feature. But then I get the same error as emk/rust-musl-builder#84