Failure to import https://github.com/nebulasio/wiki.wiki.git

String index out of range: -1
class org.xwiki.filter.FilterException: Error: An Exception was thrown.
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.readSidebar(GithubImporterInputFilterStream.java:262)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.readHierarchy(GithubImporterInputFilterStream.java:217)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.read(GithubImporterInputFilterStream.java:145)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.read(GithubImporterInputFilterStream.java:63)
    at org.xwiki.filter.input.AbstractBeanInputFilterStream.read(AbstractBeanInputFilterStream.java:79)
    at org.xwiki.filter.internal.job.FilterStreamConverterJob.runInternal(FilterStreamConverterJob.java:97)
    at org.xwiki.job.AbstractJob.runInContext(AbstractJob.java:242)
    at org.xwiki.job.AbstractJob.run(AbstractJob.java:219)
    at org.xwiki.filter.script.internal.ScriptFilterStreamConverterJob.run(ScriptFilterStreamConverterJob.java:75)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: class java.lang.StringIndexOutOfBoundsException: String index out of range: -1
    at java.lang.String.substring(String.java:1927)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.lambda$readSidebar$1(GithubImporterInputFilterStream.java:232)
    at java.util.Iterator.forEachRemaining(Iterator.java:116)
    at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
    at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.readSidebar(GithubImporterInputFilterStream.java:231)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.readHierarchy(GithubImporterInputFilterStream.java:217)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.read(GithubImporterInputFilterStream.java:145)
    at org.xwiki.contrib.githubimporter.internal.input.GithubImporterInputFilterStream.read(GithubImporterInputFilterStream.java:63)
    at org.xwiki.filter.input.AbstractBeanInputFilterStream.read(AbstractBeanInputFilterStream.java:79)
    at org.xwiki.filter.internal.job.FilterStreamConverterJob.runInternal(FilterStreamConverterJob.java:97)
    at org.xwiki.job.AbstractJob.runInContext(AbstractJob.java:242)
    at org.xwiki.job.AbstractJob.run(AbstractJob.java:219)
    at org.xwiki.filter.script.internal.ScriptFilterStreamConverterJob.run(ScriptFilterStreamConverterJob.java:75)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)