cannot build with jdk 9 ea build 124

[Roman Leventov]

[INFO] Building Chapter 0.a: Language Foundations: Basic Properties
1.0-SNAPSHOT
[INFO]
------------------------------------------------------------------------
[INFO]
[INFO] --- maven-enforcer-plugin:1.2:enforce (enforce-versions) @
jcstress-tests-chapter-0a ---
[INFO]
[INFO] --- exec-maven-plugin:1.2.1:exec (chapter0a-gen) @
jcstress-tests-chapter-0a ---
Exception in thread "main" java.lang.IllegalArgumentException: character to
be escaped is missing
        at java.util.regex.Matcher.appendExpandedReplacement(java.base at 9-ea
/Matcher.java:1020)
        at java.util.regex.Matcher.appendReplacement(java.base at 9-ea
/Matcher.java:998)
        at java.util.regex.Matcher.replaceAll(java.base at 9-ea
/Matcher.java:1181)
        at java.lang.String.replaceAll(java.base at 9-ea/String.java:2162)
        at
org.openjdk.jcstress.chapters.GeneratorUtils.writeOut(GeneratorUtils.java:38)
        at
org.openjdk.jcstress.chapters.Chapter0aTestGenerator.makeTests(Chapter0aTestGenerator.java:132)
        at
org.openjdk.jcstress.chapters.Chapter0aTestGenerator.main(Chapter0aTestGenerator.java:45)