... indicate that the expression is a CODE(xxxxx) reference. Shouldn't it be a GLOB?

With both 5.6.1 and 5.8.0 I get nothing, unless VERSION is defined in some way, in which case I get a stringified version of the glob

shell> perl -e 'print  "what? [", $main::{'VERSION'}, "]\n";'
what? []
shell> perl5.8.0 -e 'print  "what? [", $main::{'VERSION'}, "]\n";'
what? []
shell> perl -e '$VERSION=1; \
                print  "what? [", $main::{'VERSION'}, "]\n";'
what? [*main::VERSION]
shell> perl5.8.0 -e '$VERSION=1; \
                     print  "what? [", $main::{'VERSION'}, "]\n";'
what? [*main::VERSION]
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You would only get something like GLOB(0x000000) if you were stringifying a reference to a GLOB. e.g

shell> perl -e '$VERSION=1; \
                print  "what? [", \$main::{'VERSION'}, "]\n";'
what? [GLOB(0x806151c)]
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And to get something like CODE(0x000000) we need to access the CODE slot of the glob

shell> perl -e 'sub VERSION {} \
                print  "what? [", *main::VERSION{CODE}, "]\n";'
what? [CODE(0x8107f30)]
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HTH

_________
broquaint