Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Scanning on LinuxKit doesn't work when scan root is not root directory of a jarfile

See original GitHub issue

https://github.com/lukehutch/fast-classpath-scanner/blob/c07698e2b7dea93b102b35f04f369bf5e911b789/src/main/java/io/github/lukehutch/fastclasspathscanner/scanner/RelativePath.java#L224

The line indicated is getting null from nestedJarHandler, when then is wrapped and throw as an IOException. This is preventing matching classes from being processed for a jar.

2018-01-23T18:52:34.862+0000    FastClasspathScanner    -- Searching for "Class-Path:" entries within manifest files
2018-01-23T18:52:34.874+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/localedata.jar
2018-01-23T18:52:34.874+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/sunjce_provider.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/sunpkcs11.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/cldrdata.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/zipfs.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/sunec.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/jfxrt.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/nashorn.jar
2018-01-23T18:52:34.877+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/jaccess.jar
2018-01-23T18:52:34.878+0000    FastClasspathScanner    ---- Ignoring JRE jar: /usr/java/jdk1.8.0_131/jre/lib/ext/dnsns.jar
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ---- Could not canonicalize path: /acceptance-1.22-SNAPSHOT.jar!/BOOT-INF/classes
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------ java.io.IOException: Exception while getting jarfile jar:file:/acceptance-1.22-SNAPSHOT.jar!/BOOT-INF/classes
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.scanner.RelativePath.getFile(RelativePath.java:223)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.scanner.RelativePath.exists(RelativePath.java:290)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.scanner.RelativePath.isValidClasspathElement(RelativePath.java:313)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.scanner.Scanner$1.processWorkUnit(Scanner.java:235)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.scanner.Scanner$1.processWorkUnit(Scanner.java:224)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.utils.WorkQueue.runWorkLoop(WorkQueue.java:182)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.utils.WorkQueue$1.call(WorkQueue.java:147)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.utils.WorkQueue$1.call(WorkQueue.java:144)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at java.lang.Thread.run(Thread.java:748)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------ Caused by: java.lang.NullPointerException
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  at io.github.lukehutch.fastclasspathscanner.scanner.RelativePath.getFile(RelativePath.java:208)
2018-01-23T18:52:34.880+0000    FastClasspathScanner    ------  ... 11 more

This has been seen using 2.9.5 or later releases. 2.9.4 is a version that does not have this problem.