The test containers/docker/TestJcmdWithSideCar.java is failing (sometimes!) in the TMP_MOUNTED_INTO_SIDECAR mode.

It fails where the command:

docker run --tty=true --rm --cap-add=SYS_PTRACE --sig-proxy=true --pid=container:test-container-main --cap-add=NET_BIND_SERVICE --user=10668:10668 --volumes-from test-container-main jdk-internal:test-containers-docker-TestJcmdWithSideCar-jfr-jcmd /jdk/bin/jcmd -l

...gets no output, where a good run would show:

[STDOUT]
1 EventGeneratorLoop 120
24 jdk.jcmd/sun.tools.jcmd.JCmd -l

e.g.

[main-container-process] MAIN_METHOD_STARTED, argument is 120
Attach strategy TMP_MOUNTED_INTO_SIDECAR
[COMMAND]
docker run --tty=true --rm --cap-add=SYS_PTRACE --sig-proxy=true --pid=container:test-container-main --cap-add=NET_BIND_SERVICE --user=10668:10668 --volumes-from test-container-main jdk-internal:test-containers-docker-TestJcmdWithSideCar-jfr-jcmd /jdk/bin/jcmd -l
[2024-10-03T04:30:35.273416534Z] Gathering output for process 12125
[ELAPSED: 1068 ms]
[STDERR]

[STDOUT]

Full child process STDOUT was saved to docker-stdout-12125.log
[2024-10-03T04:30:36.341378706Z] Waiting for completion for process 12125
[2024-10-03T04:30:36.341534140Z] Waiting for completion finished for process 12125
[COMMAND]
docker rmi --force jdk-internal:test-containers-docker-TestJcmdWithSideCar-jfr-jcmd
[2024-10-03T04:30:36.349399928Z] Gathering output for process 12260
[ELAPSED: 27 ms]
[STDERR]

[STDOUT]
Untagged: jdk-internal:test-containers-docker-TestJcmdWithSideCar-jfr-jcmd

Full child process STDOUT was saved to docker-stdout-12260.log
----------System.err:(16/748)----------
stdout: [];
stderr: []
exitValue = 0

java.lang.RuntimeException: 'sun.tools.jcmd.JCmd' missing from stdout/stderr
at jdk.test.lib.process.OutputAnalyzer.shouldContain(OutputAnalyzer.java:253)
at TestJcmdWithSideCar.testCase01(TestJcmdWithSideCar.java:135)
at TestJcmdWithSideCar.main(TestJcmdWithSideCar.java:111)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:573)
at com.sun.javatest.regtest.agent.MainActionHelper$AgentVMRunnable.run(MainActionHelper.java:333)
at java.base/java.lang.Thread.run(Thread.java:1576)