Found while converting system tests to junit5 https://github.com/openjdk/jfx/pull/1569 :
There seems to be a format spec bug in USKeyboardTest:117
TestLogShim.waitForLog("Key typed: %0$c", new Object[] { c });

probably should be changed to

TestLogShim.waitForLog("Key typed: %04X", (int)c);

(i.e. we want to see the hex value of a char, even unprintable one)

```
java.util.IllegalFormatArgumentIndexException: Illegal format argument index = 0
at java.base/java.util.Formatter$FormatSpecifier.index(Formatter.java:2911)
at java.base/java.util.Formatter$FormatSpecifier.<init>(Formatter.java:2982)
at java.base/java.util.Formatter.parse(Formatter.java:2849)
at java.base/java.util.Formatter.format(Formatter.java:2774)
at java.base/java.util.Formatter.format(Formatter.java:2728)
at javafx.graphics@24-internal/com.sun.glass.ui.monocle.TestLogShim.waitForLog(TestLogShim.java:241)
at test.robot.com.sun.glass.ui.monocle.USKeyboardTest.checkKey(USKeyboardTest.java:117)
at test.robot.com.sun.glass.ui.monocle.USKeyboardTest.checkShift(USKeyboardTest.java:99)
at test.robot.com.sun.glass.ui.monocle.USKeyboardTest.testShift(USKeyboardTest.java:131)
```

NOTE: there is another method waitForLog(String,long) which will interfere with the proposed solution, so please keep wrapping the (int)c into Object[] code.