Error looking up function from current process on Linux

Description

JNA seems to be unable to look up functions from the current process, specifically on Linux x64, while the same code works fine on Windows x64 and macOS aarch64. The documentation says JNA should look into the current process if null is passed to Native.load.

Additional details

• The Foreign Function & Memory API from Java 22 finds all functions and all tests succeed

• nm seems to indicate the function is in the shared library, and isn't mangled

  

• The only workaround is to let JNA load the shared library by Native.load("/path/to/libzstd.so", ZstdJna.class)

Repro code

Using the Linux x64 binary found at https://github.com/freya022/discord-zstd-java/actions/runs/18886251057

public interface ZstdJna extends Library {
    ZstdJna INSTANCE = Native.load(null, ZstdJna.class);

    Pointer ZSTD_createDStream();
}

public class Repro {
    public static void main(String[] args) {
        System.load("/path/to/libzstd.so");

        ZstdJna.INSTANCE // Fine
            .ZSTD_createDStream(); // Fails
    }
}

Environment

Java Version: OpenJDK 25+36
JNA Version: 5.18.1 (also tested 4.4.0)
Operating System: Ubuntu 24.04 GitHub Actions runner (image details), also tested on a Kubuntu VM
C/C++ Compiler: GCC 13.3.0

Error

java.lang.UnsatisfiedLinkError: Error looking up function 'ZSTD_createDStream': /usr/lib/jvm/java-25-openjdk-amd64/bin/java: undefined symbol: ZSTD_createDStream
	at com.sun.jna.Function.<init>(Function.java:255)
	at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:618)
	at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:594)
	at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:580)
	at com.sun.jna.Library$Handler.invoke(Library.java:248)
	at jdk.proxy3/jdk.proxy3.$Proxy13.ZSTD_createDStream(Unknown Source)
	at dev.freya02.discord.zstd.jna.ZstdJNATest.test_decompression(ZstdJNATest.java:36)
	at java.base/java.lang.reflect.Method.invoke(Method.java:565)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)

Workflow details if necessary: https://github.com/freya022/discord-zstd-java/actions/runs/18891473842

Reproduce the Linux x64 case with Java 25, then trace NativeLibrary.getFunction and Function from the reported stack to inspect current-process symbol lookup. Compare Native.load(null, ZstdJna.class) with the explicit library workaround and the Java Foreign Function & Memory API. Done means the reported ZSTD_createDStream lookup succeeds without explicitly loading the shared library.