GrokTests#testNumericCapturesCoercion fails rarely and unreproducibly #47098
Description
The following (PR) build failed:
https://gradle-enterprise.elastic.co/s/2gxm5b5kffo22/console-log?task=:libs:elasticsearch-grok:test
org.elasticsearch.grok.GrokTests > testNumericCapturesCoercion FAILED
java.lang.IllegalArgumentException: Unable to find pattern [] in Grok's pattern dictionary
at __randomizedtesting.SeedInfo.seed([86D6B3FCB40F7F8B:D214B887E3D6771F]:0)
at org.elasticsearch.grok.Grok.toRegex(Grok.java:193)
at org.elasticsearch.grok.Grok.<init>(Grok.java:104)
at org.elasticsearch.grok.Grok.<init>(Grok.java:82)
at org.elasticsearch.grok.GrokTests.testNumericCapturesCoercion(GrokTests.java:300)
REPRODUCE WITH: ./gradlew ':libs:elasticsearch-grok:test' --tests "org.elasticsearch.grok.GrokTests.testNumericCapturesCoercion" -Dtests.seed=86D6B3FCB40F7F8B -Dtests.security.manager=true -Dtests.locale=ta-LK -Dtests.timezone=US/Indiana-Starke -Dcompiler.java=12 -Druntime.java=11
The REPRODUCE WITH line does not reproduce for me, and I have run tens of iterations of ./gradlew ':libs:elasticsearch-grok:test' --tests "org.elasticsearch.grok.GrokTests.testNumericCapturesCoercion" -Dtests.iters=10000 -Dtests.failfast=true without seeing another failure. However there are a couple of other similar failures in build-stats over the last few months too, so this wasn't a complete one-off.