test-dgram failed to find module 'dgram' on Scientific Linux 6.3

gistfile1.txt

[hnakamur@naruh lev]$ /tmp/lev/lev tests/test-dgram.lua 
/home/hnakamur/xming/lev/src/core/lib/lev.lua:221: /home/hnakamur/xming/lev/src/core/lib/module.lua:190: Failed to find module 'dgram'
	no field package.preload['dgram']
	Cannot find module /tmp/lib/lev/dgram
	Cannot find module /home/hnakamur/xming/lev/tests//modules/dgram
	Cannot find module /home/hnakamur/xming/lev/modules/dgram
	Cannot find module /home/hnakamur/xming/modules/dgram
	Cannot find module /home/hnakamur/modules/dgram
	Cannot find module /home/modules/dgram
	Cannot find module //modules/dgram
stack traceback:
	[C]: in function 'error'
	/home/hnakamur/xming/lev/src/core/lib/module.lua:190: in function 'require'
	/home/hnakamur/xming/lev/tests/test-dgram.lua:20: in function 'fn'
	/home/hnakamur/xming/lev/src/core/lib/module.lua:67: in function 'myloadfile'
	/home/hnakamur/xming/lev/src/core/lib/lev.lua:321: in function </home/hnakamur/xming/lev/src/core/lib/lev.lua:221>
	[C]: in function 'xpcall'
	/home/hnakamur/xming/lev/src/core/lib/lev.lua:221: in main chunk
	[C]: in function 'require'
	[string "    local path = require('uv_native').execpat..."]:1: in main chunk
WARNING: forgot to close luv_tty lhandle=0x40098ce0 handle=0x2409150

dgram.lua is placed at /home/hnakamur/xming/lev/src/core/lib/dgram.lua.
So the module search path should have contain /home/hnakamur/xming/lev/src/core/lib.