some jdk/javadoc/doclet tests fail (JDK 15)

A couple of javadoc tests started to fail 2 days ago in our nightly tests (on all platforms).
2 of them fail in jdk15 too (all 3 in JDK16).


jdk/javadoc/doclet/testGeneratedBy/TestGeneratedBy.java
stderr says :

java.lang.Error: 20 of 68 subtests failed, in 2 runs of javadoc
at javadoc.tester.JavadocTester.printSummary(JavadocTester.java:915)
at javadoc.tester.JavadocTester.runTests(JavadocTester.java:283)
at javadoc.tester.JavadocTester.runTests(JavadocTester.java:259)
at TestGeneratedBy.main(TestGeneratedBy.java:40)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)

Those 2 fail too :

jdk/javadoc/doclet/testHeadTag/TestHeadTag.java

java.lang.Error: 2 of 10 subtests failed, in 2 runs of javadoc
at javadoc.tester.JavadocTester.printSummary(JavadocTester.java:915)
at javadoc.tester.JavadocTester.runTests(JavadocTester.java:283)
at TestHeadTag.main(TestHeadTag.java:51)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)

jdk/javadoc/doclet/testVersionOption/TestVersionOption.java

stdout :

Running test testFullVersionOption
Running javadoc...
args: [--full-version]
javadoc OUT:
javadoc full version "16.0.0.1-internal+0-adhoc.openjdk.jdk"

Starting subtest 1.1: Check links
  Checked 0 files.
  Found 0 references to 0 anchors in 0 files and 0 other URIs.
       0 missing files
       0 duplicate ids
       0 missing ids
Passed: Links are OK

Starting subtest 1.2: Check accessibility
All headings OK
All regions OK
Passed: No accessibility errors found

Starting subtest 1.3: check exit code
Passed: return code 0

Starting subtest 1.4: checkOutput
Passed: OUT: following text found:
javadoc full version "16.0.0.1-internal+0-adhoc.openjdk.jdk"


Running test testVersionOption
Running javadoc (run 2)...
args: [--version]
javadoc OUT:
javadoc 16-internal

Starting subtest 2.1: Check links
  Checked 0 files.
  Found 0 references to 0 anchors in 0 files and 0 other URIs.
       0 missing files
       0 duplicate ids
       0 missing ids
Passed: Links are OK

Starting subtest 2.2: Check accessibility
All headings OK
All regions OK
Passed: No accessibility errors found

Starting subtest 2.3: check exit code
Passed: return code 0

Starting subtest 2.4: checkOutput
FAILED: OUT: following text not found:
javadoc 16.0.0.1-internal
found
javadoc 16-internal
        at javadoc.tester.JavadocTester.checkOutput(JavadocTester.java:520)
        at javadoc.tester.JavadocTester.checkOutput(JavadocTester.java:506)
        at TestVersionOption.testVersionOption(TestVersionOption.java:57)

stderr :

java.lang.Error: 1 of 8 subtests failed, in 2 runs of javadoc
at javadoc.tester.JavadocTester.printSummary(JavadocTester.java:915)
at javadoc.tester.JavadocTester.runTests(JavadocTester.java:283)
at javadoc.tester.JavadocTester.runTests(JavadocTester.java:259)
at TestVersionOption.main(TestVersionOption.java:40)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)