Plugin execution fails to read linked schema file if path contains non-ascii characters

[reftel]

If a project is in a directory containing a non-ASCII character, plugin execution fails when trying to read a linked shcema file, with the following stack trace (some paths mangled; stack trace is for 3.1.0, but 2.5.0 has similar issues):

[WARNING]  Parameter 'arguments' (user property 'xjc.arguments') is deprecated: This should be removed in the 2.0+ release, as all arguments should be handled by other parameters.
[INFO] Created EpisodePath [/Users/blabla/æøå/target/generated-sources/jaxb/META-INF/JAXB]: true
[INFO] Created EpisodePath [/Users/blabla/æøå/target/generated-sources/jaxb/META-INF/JAXB]: true
[WARNING] file:/Users/blabla/æøå/src/main/resources/mets/submissionDescription.xsd [175,85] 
org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'xlink.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException (ErrorHandlerWrapper.java:204)
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.warning (ErrorHandlerWrapper.java:100)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError (XMLErrorReporter.java:392)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaErr (XSDHandler.java:4253)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.reportSchemaWarning (XSDHandler.java:4244)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.resolveSchema (XSDHandler.java:2111)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.constructTrees (XSDHandler.java:1049)
    at com.sun.org.apache.xerces.internal.impl.xs.traversers.XSDHandler.parseSchema (XSDHandler.java:652)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadSchema (XMLSchemaLoader.java:617)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGrammar (XMLSchemaLoader.java:576)
    at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGrammar (XMLSchemaLoader.java:542)
    at com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchemaFactory.newSchema (XMLSchemaFactory.java:276)
    at com.sun.tools.xjc.reader.xmlschema.parser.SchemaConstraintChecker.check (SchemaConstraintChecker.java:81)
    at com.sun.tools.xjc.ModelLoader.loadXMLSchema (ModelLoader.java:301)
    at com.sun.tools.xjc.ModelLoader.load (ModelLoader.java:121)
    at com.sun.tools.xjc.ModelLoader.load (ModelLoader.java:76)
    at com.sun.tools.xjc.Driver.run (Driver.java:324)
    at org.codehaus.mojo.jaxb2.javageneration.AbstractJavaGeneratorMojo.performExecution (AbstractJavaGeneratorMojo.java:476)
    at org.codehaus.mojo.jaxb2.AbstractJaxbMojo.execute (AbstractJaxbMojo.java:337)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328)
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
    at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
    at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
    at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:73)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:53)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:118)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:261)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:173)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:101)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:906)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:283)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:206)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:283)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:226)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:407)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:348)

The failure to find the schema document then leads to a number of other issues.

When the directory is renamed to not contain non-ASCII characters, everything works as intended.