Hi Guix, we have a problem with jar manifests. When we use the Class-Path property to ensure that an executable can find its dependencies on the class path at run-time, we end up with a manifest like this:
--8<---------------cut here---------------start------------->8--- Manifest-Version: 1.0 Class-Path: /gnu/store/i28vi94r8z9f0x02zgkrv87w16ibmqkw-java-htsjdk-2. 10.1/share/java/htsjdk.jar Created-By: 1.8.0_151 (Oracle Corporation) Main-Class: picard.cmdline.PicardCommandLine --8<---------------cut here---------------end--------------->8--- Note that the Class-Path property is broken into two lines. This means that the reference scanner will miss it and grafting will fail. Breaking up lines longer than 70 characters is according to the manifest specification, see https://docs.oracle.com/javase/7/docs/technotes/guides/jar/jar.html We cannot just use a wrapper that sets CLASSPATH, because it appears to be ignored when using a manifest with “Main-Class”. “Main-Class” is required for executables that can be run like this: java -jar whatever.jar A possible work-around might be to patch the class loader of our JDKs to look at a custom Guix-specific file, which we will include in each jar. That file would be allowed to have longer lines. There are two disadvantages: 1) we need to patch the JDK 2) the jars would not do the right thing when executed with a different JDK (e.g. on a foreign distro). What do you think? -- Ricardo
