Spotbugs detects the EQ_ALWAYS_TRUE issue in the following code.

class AlwaysTrueEquals {

    @Override
    public boolean equals(Object obj) {
        return true;
    }

    @Override
    public int hashCode() {
        return 42;
    }

    public static void main(String[] args) {
        AlwaysTrueEquals obj1 = new AlwaysTrueEquals();
        AlwaysTrueEquals obj2 = new AlwaysTrueEquals();

        System.out.println("obj1.equals(obj2): " + obj1.equals(obj2));
        System.out.println("obj2.equals(obj1): " + obj2.equals(obj1));
    }
}

However, if the equals method is re-written as the following, the error is no longer raised. The updates do not seem to have changed the return value in anyway, it's still a hard-coded true returned. I am not sure if this is a bug or if I'm doing anything silly, because the code seems very simple.

@Override
public boolean equals(Object obj) {
    boolean checkEqual = (obj instanceof AlwaysTrueEquals);
    System.out.println(checkEqual);
    return true;
}

Exactly similar issue is also observable with EQ_ALWAYS_FALSE as well.
Note: The (obj instanceof AlwaysTrueEquals) is completely optional and the issue is reproducible without this. It is only added to suppress the EQ_UNUSUAL error.

Spotbugs: 4.9.3
Java: Jdk 17 and Jdk 21
Run Method: CLI as:

javac AlwaysTrueEquals.java && \
    java -jar $SPOTBUGS_JAR -textui -effort:max *.class