Why need another user when install rvm under current user on Vagrant?

Question

Added a user named deploy in Vagrant. Then change to deploy user:

vagrant@vagrant:~$ su - deploy
deploy@vagrant:~$ 

Now install rvm :

deploy@vagrant:~$ gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
gpg: directory `/home/deploy/.gnupg' created
gpg: new configuration file `/home/deploy/.gnupg/gpg.conf' created
gpg: WARNING: options in `/home/deploy/.gnupg/gpg.conf' are not yet active during this run
gpg: keyring `/home/deploy/.gnupg/secring.gpg' created
gpg: keyring `/home/deploy/.gnupg/pubring.gpg' created
gpg: requesting key D39DC0E3 from hkp server keys.gnupg.net
gpg: /home/deploy/.gnupg/trustdb.gpg: trustdb created
gpg: key D39DC0E3: public key "Michal Papis (RVM signing) <mpapis@gmail.com>" imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)
deploy@vagrant:~$ curl -sSL https://get.rvm.io | bash -s stable
mktemp: failed to create file via template ‘/home/vagrant/.rvm/rvm-exec-test.XXXXXX’: Permission denied

Why it said this directory:

/home/vagrant/... : Permission denied

I have read the install script:

https://raw.githubusercontent.com/wayneeseguin/rvm/master/binscripts/rvm-installer

But don't know why.

Answer 1

you still run it from /home/vagrant/ so after you did

vagrant@vagrant:~$ su - deploy
deploy@vagrant:~$ 

you need to do

deploy@vagrant:~$ cd

so it will go to the home folder of deploy user and will install there