CTW failed in nightlies with:

1.
Exception in thread "main" java.lang.AssertionError
at sun.hotspot.tools.ctw.Utils.fileNameToClassName(Utils.java:209)
at java.util.stream.ReferencePipeline$3$1.accept(java.base@9-internal/ReferencePipeline.java:195)
at java.util.stream.ReferencePipeline$2$1.accept(java.base@9-internal/ReferencePipeline.java:177)
at java.util.stream.ReferencePipeline$2$1.accept(java.base@9-internal/ReferencePipeline.java:177)
at java.util.Spliterators$ArraySpliterator.forEachRemaining(java.base@9-internal/Spliterators.java:948)
at java.util.stream.AbstractPipeline.copyInto(java.base@9-internal/AbstractPipeline.java:484)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(java.base@9-internal/AbstractPipeline.java:474)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(java.base@9-internal/ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(java.base@9-internal/ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(java.base@9-internal/AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(java.base@9-internal/ReferencePipeline.java:430)
at sun.hotspot.tools.ctw.ClassPathJimageEntry.process(ClassPathJimageEntry.java:63)
at sun.hotspot.tools.ctw.CompileTheWorld.main(CompileTheWorld.java:84)

2.
Exception in thread "main" java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet
at java.lang.ClassLoader.defineClass1(java.base@9-internal/Native Method)
at java.lang.ClassLoader.defineClass(java.base@9-internal/ClassLoader.java:942)
at java.security.SecureClassLoader.defineClass(java.base@9-internal/SecureClassLoader.java:150)
at java.net.URLClassLoader.defineClass(java.base@9-internal/URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(java.base@9-internal/URLClassLoader.java:78)
at java.net.URLClassLoader$1.run(java.base@9-internal/URLClassLoader.java:375)
at java.net.URLClassLoader$1.run(java.base@9-internal/URLClassLoader.java:369)
at java.security.AccessController.doPrivileged(java.base@9-internal/Native Method)
at java.net.URLClassLoader.findClass(java.base@9-internal/URLClassLoader.java:368)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:486)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:419)
at java.lang.ClassLoader.defineClass1(java.base@9-internal/Native Method)
at java.lang.ClassLoader.defineClass(java.base@9-internal/ClassLoader.java:942)
at java.security.SecureClassLoader.defineClass(java.base@9-internal/SecureClassLoader.java:150)
at java.net.URLClassLoader.defineClass(java.base@9-internal/URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(java.base@9-internal/URLClassLoader.java:78)
at java.net.URLClassLoader$1.run(java.base@9-internal/URLClassLoader.java:375)
at java.net.URLClassLoader$1.run(java.base@9-internal/URLClassLoader.java:369)
at java.security.AccessController.doPrivileged(java.base@9-internal/Native Method)
at java.net.URLClassLoader.findClass(java.base@9-internal/URLClassLoader.java:368)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:486)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:419)
at sun.hotspot.tools.ctw.PathHandler.processClass(PathHandler.java:153)
at sun.hotspot.tools.ctw.ClassPathJarEntry.processJarEntry(ClassPathJarEntry.java:76)
at sun.hotspot.tools.ctw.ClassPathJarEntry.process(ClassPathJarEntry.java:63)
at sun.hotspot.tools.ctw.CompileTheWorld.main(CompileTheWorld.java:84)
Caused by: java.lang.ClassNotFoundException: javax.servlet.http.HttpServlet
at java.net.URLClassLoader.findClass(java.base@9-internal/URLClassLoader.java:388)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:486)
at java.lang.ClassLoader.loadClass(java.base@9-internal/ClassLoader.java:419)
... 26 more