Cannot create cache directory /home/ubuntu/.composer/cache/repo/https---repo.packagist.org/, or directory is not writable. Proceeding without cache 权限报错
sudo chown -R $USER ~/.composer/
Cannot create cache directory /home/ubuntu/.composer/cache/files/, or directory is not writable. Proceeding without cache 也是权限问题
sudo chmod -R 777 /home/ubuntu/.composer/cache/files/