Relation 'has' with requirement '' is not supported

hello has anyone an idea what this could mean? : "Relation 'has' with requirement '' is not supported.." i tried to run "pear install Cache", which produced that message. on the other hand Cache_Lite installation worked well. i am on win2k using pear from the 4.2.3 dist. -urs ***** C:\php>pear install Cache_Lite downloading http://pear.php.net/get/Cache_Lite ... ...done: 16,349 bytes installed file c:\php\doc\pear\Cache_Lite\Cache\docs\technical installed file c:\php\doc\pear\Cache_Lite\Cache\docs\examples installed file c:\php\doc\pear\Cache_Lite\Cache\tests\readme installed file c:\php\pear\Cache\Lite\Output.php installed file c:\php\pear\Cache\Lite\Function.php installed file c:\php\pear\Cache\Lite.php installed file c:\php\doc\pear\Cache_Lite\Cache\LICENSE install ok C:\php>pear install Cache downloading http://pear.php.net/get/Cache ... ...done: 28,806 bytes Relation 'has' with requirement '' is not supported Dependencies failed C:\php>pear install Net_SMTP downloading http://pear.php.net/get/Net_SMTP ... ...done: 2,883 bytes Relation 'has' with requirement '' is not supported Dependencies failed C:\php>