The javadoc manpage (nroff version) was just updated with changes made in earlier issues like JDK-8275146, and as a result of these updates the test:

langtools/jdk/javadoc/tool/CheckManPageOptions.java

is now failing.

----------System.err:(354/9931)*----------
File: /System/Volumes/Data/mesos/work_dir/jib-master/install/jdk-18+28-1959/src.full/open/src/jdk.javadoc/share/man/javadoc.1

found:
.IP \\[bu] 2
\\f[CB]\\-\\-add\\-modules\\f[R]

found:
.IP \\[bu] 2
\\f[CB]\\-bootclasspath\\f[R]

found:
.IP \\[bu] 2
\\f[CB]\\-\\-class\\-path\\f[R], \\f[CB]\\-classpath\\f[R], or \\f[CB]\\-cp\\f[R]
...

I suspect formatting changes have disrupted what the test is looking for.