According to libhdfs doc, wildcard in CLASSPATH is not support:
The most common problem is the CLASSPATH is not set properly when calling a program that uses libhdfs. Make sure you set it to all the Hadoop jars needed to run Hadoop itself as well as the right configuration directory containing hdfs-site.xml. It is not valid to use wildcard syntax for specifying multiple jars. It may be useful to run hadoop classpath --glob or hadoop classpath --jar <path> to generate the correct classpath for your deployment.