Bench build Error "Unexpected end of JSON input"

Frappe Framework Website
1

hello, bench build give me error after clean install.

bench version
erpnext 10.1.76
foundation 0.0.1
frappe 10.1.68

/home/ubuntu/frappe-bench/apps/frappe/frappe/build.py:106: UserWarning: Source /home/ubuntu/frappe-bench/apps/frappe_io/frappe_io/docs does not exists.
warnings.warn(‘Source {source} does not exists.’.format(source = source))
/home/ubuntu/frappe-bench/apps/frappe/frappe/build.py:106: UserWarning: Source /home/ubuntu/frappe-bench/apps/foundation/foundation/docs does not exists.
warnings.warn(‘Source {source} does not exists.’.format(source = source))
/home/ubuntu/frappe-bench/apps/frappe/frappe/build.py:106: UserWarning: Source /home/ubuntu/frappe-bench/apps/wform/wform/docs does not exists.
warnings.warn(‘Source {source} does not exists.’.format(source = source))
SyntaxError: Unexpected end of JSON input