Bug 39720 Adding external jar to the Build Path of an existing Java project [build path]
When adding an external jar file to an existing Java project, the "Setting Build Path" error dialog is displayed. The dialog displays the text "An error occured while setting the build path. Reason: /usr does not exist". The jar to be added in this case is located in the /usr/local/bin/ directory. I am working with the release 2.1 build for linux.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/CPListElement.java
public Object getAttribute(String key) {
		CPListElementAttribute attrib= findAttributeElement(key);
		if (attrib != null) {
			return attrib.getValue();
		}
		return null;
	}
	
	private void createAttributeElement(String key, Object value) {
		fChildren.add(new CPListElementAttribute(this, key, value));
	}	
	
	
	public Object[] getChildren(boolean hideOutputFolder) {
		if (hideOutputFolder && fEntryKind == IClasspathEntry.CPE_SOURCE) {
			return new Object[] { findAttributeElement(EXCLUSION) };
		}
		return fChildren.toArray();
	}
	
	private void setParentContainer(CPListElement element) {
		fParentContainer= element;
	}
	
	public CPListElement getParentContainer() {
		return fParentContainer;
	}	
	
	private void attributeChanged(String key) {