Jni provider fails on linux

[jvalkeal]

I'm still debugging this issue on my side but I wanted to throw this out here if it immediately rings a bell.

When trying to use 3.24.1 I'm getting into trouble with tests(where I don't have a proper tty). I get jni and exec and then jni fails with newTerminal with

java: symbol lookup error: /tmp/jlinenative-3.24.1-e342cc4f6f2aa9de-libjlinenative.so: undefined symbol: openpty

If I run my cli in a real terminal and attach debugger, I have jni, jansi, jna and exec but jni doesn't fail with sysTerminal and I get PosixSysTerminal.

I'm on Ubuntu 18.04.6 LTS in this system.

[jvalkeal]

So it looks to be CLibrary.openpty() in LinuxNativePty.open() which throws that hard error if org.jline:jline-terminal-jna is in a classpath. If jna is not in a classpath then newTerminal throws NoClassDefFoundError and JLine catches that and moves on.

[gnodet]

Not sure to understand, is the problem with the JNI provider or the JNA provider ? Or are those two different problems ?

[jvalkeal]

I'm a bit rusty with this jni stuff so give me some rope here. Looks like when this /tmp/jlinenative-3.24.1-e342cc4f6f2aa9de-libjlinenative.so is extracted and used this call

https://github.com/jline/jline3/blob/bf698ba5fe46e190616dce9284c92e8e49079c15/terminal-jni/src/main/java/org/jline/terminal/impl/jni/linux/LinuxNativePty.java#L46-L51

doesn't work. Looking ldd:

$ ldd /tmp/jlinenative-3.24.1-e342cc4f6f2aa9de-libjlinenative.so
    linux-vdso.so.1 (0x00007fff87b3c000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fc9d0365000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fc9d0959000)

I don't see it linking to libutil where I think openpty is. If I do:

export LD_PRELOAD=/lib/x86_64-linux-gnu/libutil.so.1

before build then the error goes away.

[jvalkeal]

Quickest way to see this in JLine itself is to force system to false and run demo. Felix sets system to true so I had to tweak a code.

$ git diff
diff --git a/terminal/src/main/java/org/jline/terminal/TerminalBuilder.java b/terminal/src/main/java/org/jline/terminal/TerminalBuilder.java
index 64708c7d..a08d5ea0 100644
--- a/terminal/src/main/java/org/jline/terminal/TerminalBuilder.java
+++ b/terminal/src/main/java/org/jline/terminal/TerminalBuilder.java
@@ -148,7 +148,7 @@ public final class TerminalBuilder {
     private String type;
     private Charset encoding;
     private int codepage;
-    private Boolean system;
+    private Boolean system = false;
     private SystemOutput systemOutput;
     private String provider;
     private String providers;
@@ -179,7 +179,7 @@ public final class TerminalBuilder {
     }

     public TerminalBuilder system(boolean system) {
-        this.system = system;
+        // this.system = system;
         return this;
     }

13:07 $ ./build demo
Launching Gogo JLine...
Classpath: /home/jvalkealahti/repos/jvalkeal/jline3/demo/target/classes:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-terminal-jni-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-terminal-jansi-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-console-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-remote-telnet-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-terminal-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-builtins-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-style-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-remote-ssh-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-terminal-jna-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-terminal-ffm-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-reader-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-native-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/jline-groovy-3.24.2-SNAPSHOT.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/org.apache.felix.gogo.runtime-1.1.6.jar:/home/jvalkealahti/repos/jvalkeal/jline3/demo/target/lib/org.apache.felix.gogo.jline-1.1.8.jar
java: symbol lookup error: /tmp/jlinenative-3.24.2-349cf11782093e50-libjlinenative.so: undefined symbol: openpty

In my issue above I used custom streams(for doing testing), so it ended up calling:

https://github.com/jline/jline3/blob/bf698ba5fe46e190616dce9284c92e8e49079c15/terminal/src/main/java/org/jline/terminal/TerminalBuilder.java#L485-L486

[gnodet]

Sorry for the delay. The thing I'm wondering about, is how to change the makefile so that the libraries are linked with libutil...

[dattasid]

You may need to load required libraries explicitly whenever you use Linker.nativeLinker() . Linker.defaultLookup() behaves differently depending on architecture, I dont think it is reliable.