CustomLauncherTest fails as its unable to find the launcher executable on Alpine Linux 11

java.io.IOException: Cannot run program "/home/jenkins/workspace/Test_openjdk11_hs_extended.openjdk_x86-64_alpine-linux/aqa-tests/TKG/output_16425959244573/jdk_management_0/work/scratch/13/launcher": error=2, No such file or directory
at java.base/java.lang.ProcessBuilder.start(ProcessBuilder.java:1128)
at java.base/java.lang.ProcessBuilder.start(ProcessBuilder.java:1071)
at jdk.testlibrary.ProcessTools.startProcess(ProcessTools.java:162)
at jdk.testlibrary.ProcessTools.startProcess(ProcessTools.java:129)
at CustomLauncherTest.main(CustomLauncherTest.java:130)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.io.IOException: error=2, No such file or directory
at java.base/java.lang.ProcessImpl.forkAndExec(Native Method)
at java.base/java.lang.ProcessImpl.(ProcessImpl.java:340)
at java.base/java.lang.ProcessImpl.start(ProcessImpl.java:271)
at java.base/java.lang.ProcessBuilder.start(ProcessBuilder.java:1107)
... 10 more

JavaTest Message: Test threw exception: java.io.IOException: Cannot run program "/home/jenkins/workspace/Test_openjdk11_hs_extended.openjdk_x86-64_alpine-linux/aqa-tests/TKG/output_16425959244573/jdk_management_0/work/scratch/13/launcher": error=2, No such file or directory
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.io.IOException: Cannot run program "/home/jenkins/workspace/Test_openjdk11_hs_extended.openjdk_x86-64_alpine-linux/aqa-tests/TKG/output_16425959244573/jdk_management_0/work/scratch/13/launcher": error=2, No such file or directory

Start with CustomLauncherTest.java at line 130 and trace how the launcher executable is created before ProcessTools.startProcess runs it. Reproduce the failure on Alpine Linux and determine why the executable cannot be found; done means the test runs successfully there without the reported IOException.

Written by the indexing model from the issue text.