A very confusing error！

[csufangyu]

hi
I apologize for your interruption again，but I get a very confusing error.I can not understand!
when I run the ./build,I get a error as fellows:
robot@robot:~/Robot_Project/drakon.tech$ sudo tclsh ./build

Building "lua" files: "/home/robot/Robot_Project/drakon.tech/app"
Minifying Javascript files
/home/robot/Robot_Project/drakon.tech/clos
/home/robot/Robot_Project/drakon.tech/tmp/dkt/static
ContextMenu.js
/home/robot/Robot_Project/drakon.tech/static/ContextMenu.js
ContextMenu.js... couldn't execute "java": no such file or directory
while executing
"exec java -jar /home/robot/Robot_Project/drakon.tech/clos/compiler.jar --js_output_file=/home/robot/Robot_Project/drakon.tech/tmp/dkt/static/$file_onl..."
("foreach" body line 13)
invoked from within
"foreach file $jsfiles {
set file_only [ file tail $file ]
if {$file_only != "loader.js"} {
# puts "1"
puts $closdir
puts $outdir
puts $file_o..."
(file "./build" line 105)

and I try to check my envoriment, so I run the code on terminal. I don't get error.my code is:
% set reslut [java -jar ./clos/compiler.jar --js_output_file=/home/robot/Robot_Project/drakon.tech/tmp/dkt/static/ContextMenu.js /home/robot/Robot_Project/drakon.tech/static/ContextMenu.js]

It is very confusing!