From dd2a8b899a272de6f3b9c1514a6feda4725571f7 Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <magnusu@met.no>
Date: Thu, 17 Oct 2024 22:15:48 +0200
Subject: [PATCH] Use extern crate to force linkage

---
 hdf5-src/src/lib.rs | 3 +++
 hdf5-sys/Cargo.toml | 2 +-
 hdf5-sys/build.rs   | 3 ---
 hdf5-sys/src/lib.rs | 7 +++++++
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/hdf5-src/src/lib.rs b/hdf5-src/src/lib.rs
index e39a2b152..174659f55 100644
--- a/hdf5-src/src/lib.rs
+++ b/hdf5-src/src/lib.rs
@@ -1 +1,4 @@
 //! Dummy crate for building HDF5 C library from source.
+
+#[cfg(feature = "zlib")]
+extern crate libz_sys;
diff --git a/hdf5-sys/Cargo.toml b/hdf5-sys/Cargo.toml
index 5fefdc1d1..4397ee6db 100644
--- a/hdf5-sys/Cargo.toml
+++ b/hdf5-sys/Cargo.toml
@@ -27,7 +27,7 @@ default = []
 mpio = ["dep:mpi-sys"]
 hl = ["hdf5-src?/hl"]
 threadsafe = ["hdf5-src?/threadsafe"]
-zlib = ["libz-sys", "hdf5-src?/zlib"]
+zlib = ["dep:libz-sys", "hdf5-src?/zlib"]
 static = ["dep:hdf5-src"]
 deprecated = ["hdf5-src?/deprecated"]
 
diff --git a/hdf5-sys/build.rs b/hdf5-sys/build.rs
index b735f4605..5cb4238eb 100644
--- a/hdf5-sys/build.rs
+++ b/hdf5-sys/build.rs
@@ -734,9 +734,6 @@ fn get_build_and_emit() {
     if feature_enabled("ZLIB") {
         let zlib_lib = env::var("DEP_HDF5SRC_ZLIB").unwrap();
         println!("cargo::metadata=zlib={}", &zlib_lib);
-        let zlib_lib_header = env::var("DEP_HDF5SRC_ZLIB").unwrap();
-        println!("cargo::metadata=zlib={}", &zlib_lib_header);
-        println!("cargo::rustc-link-lib=static={}", &zlib_lib);
     }
 
     if feature_enabled("HL") {
diff --git a/hdf5-sys/src/lib.rs b/hdf5-sys/src/lib.rs
index f29df8cdd..867bb14c9 100644
--- a/hdf5-sys/src/lib.rs
+++ b/hdf5-sys/src/lib.rs
@@ -8,6 +8,13 @@
 #![allow(clippy::module_name_repetitions)]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 
+#[cfg(feature = "static")]
+extern crate hdf5_src;
+#[cfg(feature = "zlib")]
+extern crate libz_sys;
+#[cfg(feature = "mpio")]
+extern crate mpi_sys;
+
 macro_rules! extern_static {
     ($dest:ident, $src:ident) => {
         extern "C" {