How to use the JSTL "if" tag without getting "..attribute test does not accept any expressions"

How would I make the following code work?

        <c:if test="${null != searchResults}" >
            <c:forEach items="${searchResults}" var="result" varStatus="status">

I've tried many different variations of this, such as:

<c:if test="${searchWasPerformed}" >

or

<c:if test="<%=request.getAttribute("searchWasPerformed") %>" >

and even

<% boolean b = null != request.getAttribute("searchResults"); %>
    <c:if test="${b}" >

Which looks REALLY ugly :/ But I keep on getting the

org.apache.jasper.JasperException: /WEB-INF/jsp/admin/admin-index.jsp(29,2) PWC6236: According to TLD or attribute directive in tag file, attribute test does not accept any expressions

How would I go around this?