Troubleshooting

JPL not included in SWIPL compilation

For JPL to be included in the compilation, CMAKE has to be able to find Java and JNI:

- Found JNI: /usr/lib/jvm/java-11-openjdk-amd64/lib/libjawt.so  
-- JNI_INCLUDE_DIRS=/usr/lib/jvm/java-11-openjdk-amd64/include;/usr/lib/jvm/java-11-openjdk-amd64/include/linux;/usr/lib/jvm/java-11-openjdk-amd64/include
-- JNI_LIBRARIES=/usr/lib/jvm/java-11-openjdk-amd64/lib/libjawt.so;/usr/lib/jvm/java-11-openjdk-amd64/lib/server/libjvm.so

-- Found Java: /usr/bin/java (found version "11.0.7") found components:  Development 

While Java can be found if it is installed, finding JNI requires having JAVA_HOME set:

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64/

Cannot find libjvm.so (Prolog-calls-Java)

When loading JPL module in Prolog:

?- use_module(library(jpl)).
ERROR: /usr/lib/swi-prolog/library/jpl.pl:4243:
	'$open_shared_object'/3: libjvm.so: cannot open shared object file: No such file or directory
ERROR: /usr/lib/swi-prolog/library/jpl.pl:4243:
	/usr/lib/swi-prolog/library/jpl.pl:4243: Initialization goal raised exception:
	library `java' does not exist (Please add directory holding libjava.so to $LD_LIBRARY_PATH)
ERROR: Exported procedure jpl:jpl_c_lib_version/1 is not defined
true.

Do a locate libjvm.so to find where it is and add the path to LD_LIBRARY_PATH so that library can be found:

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/jvm/java-8-oracle/jre/lib/amd64/server/

or for OpenJDK

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/jvm/java-11-openjdk-amd64/lib/server/

FATAL ERROR: Could not find system resources

System is unable to find the SWI Prolog framework, including failing to find library libswipl.so.

Set-up:

• SWI_HOME_DIR: the location where SWI-Prolog is installed.
  • In Ubuntu distribution: /usr/lib/swi-prolog/
  • In local install for example: /usr/local/swipl/lib/swipl/
• SWIPL_BOOT_FILE: location of the .prc booting file.
  • In Ubuntu distribution: /usr/lib/swi-prolog/boot64.prc
  • In local install for example: /usr/local/swipl/lib/swipl/

Run-time error: process.so: undefined symbol: Sfilefunctions

You need to tell the system to pre-load SWI main library:

export LD_PRELOAD=/home/ssardina/git/soft/prolog/swipl-devel.git/build/src/libswipl.so

Check this post and what is preloading?

Error "undefined symbol: PL_new_atom" when reading files #10

Check this post.

This is resovled by loading libswipl.so before by setting LD_PRELOAD as above.

ERROR source_sink `jar('jpl.jar')' does not exist

Some Prolog file is not able to find jpl.jar that it needs to call some class. We need to setup CLASSPATH to point to JPL:

export CLASSPATH=</path/to/build>/packages/jpl/src/java/jpl.jar

That is the JAR file that CMAKE produces and the Prolog test code needs to be able to find it.