Thank you very much. This is all working as it should now.

May I be cheeky and further the question by explaining the actual problem I am (was) trying to solve with this?

I have a program which uses XML::LibXML and some of its constants (e.g. XML_ELEMENT_NODE). I want to modify the program to make it work on systems which do not have XML::LibXML installed and just make the functionality which require this module unavailable. The problem I faced: Even though I could put the 'require & import XML::LibXML' statements into an eval block, the compiler still moaned about me using Barewords (the now non-available XML::LibXML::Common constants).

I have solved this problem as follows now, but am wondering if there is a "cleaner" approach to this rather than just importing "fake" constants from another package with a zero value instead.

#!/usr/bin/perl -w
BEGIN {
        package LibXMLVars;
        require Exporter;
        our @ISA = qw(Exporter);
        our @EXPORT_OK = qw(XML_ELEMENT_NODE XML_ATTRIBUTE_NODE XML_TE
+XT_NODE XML_CDATA_SECTION_NODE);
        use constant XML_ELEMENT_NODE => 0;
        use constant XML_ATTRIBUTE_NODE => 0;
        use constant XML_TEXT_NODE => 0;
        use constant XML_CDATA_SECTION_NODE => 0;
}
package main;
use strict;
BEGIN {
        eval {
                require XML::LibXML;
                import XML::LibXML;
                require XML::LibXML::Common;
                import XML::LibXML::Common qw(:libxml);
        };
        if ($@) {
                warn "Failed to import XML::LibXML";
                import LibXMLVars qw(XML_ELEMENT_NODE XML_ATTRIBUTE_NO
+DE XML_TEXT_NODE XML_CDATA_SECTION_NODE);
        }
}

print "Test: '".XML_ELEMENT_NODE."'\n";
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