Error in Install

I got this when trying to install in ubuntu 12.04.
I followed these 2 steps

wget https://raw.githubusercontent.com/frappe/bench/master/install_scripts/setup_frappe.sh
sudo bash setup_frappe.sh --setup-production

How can I solve this ?

Traceback (most recent call last):
File “/usr/local/bin/bench”, line 9, in
load_entry_point(‘bench==0.1’, ‘console_scripts’, ‘bench’)()
File “/home/superbotics/bench-repo/bench/cli.py”, line 55, in cli
bench()
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 664, in call
return self.main(*args, **kwargs)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 644, in main
rv = self.invoke(ctx)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 991, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 837, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 464, in invoke
return callback(*args, **kwargs)
File “/home/superbotics/bench-repo/bench/cli.py”, line 158, in init
no_auto_update=no_auto_update, frappe_path=frappe_path, frappe_branch=frappe_branch)
File “/home/superbotics/bench-repo/bench/utils.py”, line 61, in init
setup_backups(bench=path)
File “/home/superbotics/bench-repo/bench/utils.py”, line 155, in setup_backups
logfile=os.path.join(get_bench_dir(bench=bench), ‘logs’, ‘backup.log’)))
File “/home/superbotics/bench-repo/bench/utils.py”, line 158, in add_to_crontab
current_crontab = read_crontab()
File “/home/superbotics/bench-repo/bench/utils.py”, line 166, in read_crontab
s = subprocess.Popen([“crontab”, “-l”], stdin=subprocess.PIPE, stdout=subprocess.PIPE)
File “/usr/lib/python2.7/subprocess.py”, line 679, in init
errread, errwrite)
File “/usr/lib/python2.7/subprocess.py”, line 1249, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory