Installing RVM: getting error "There was an error(23)." - ruby

Question

I am trying to install Ruby Version Manager (RVM) without success.
How to get through this error I am getting?
ubuntu#ip-172-31-0-20:/tmp$ rvm install ruby-1.9.3-p484
Searching for binary rubies, this might take some time.
No binary rubies available for: ubuntu/14.04/x86_64/ruby-1.9.3-p484.
Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
Checking requirements for ubuntu.
Requirements installation successful.
Installing Ruby from source to: /usr/local/rvm/rubies/ruby-1.9.3-p484, this may take a while depending on your cpu(s)...
ruby-1.9.3-p484 - #downloading ruby-1.9.3-p484, this may take a while depending on your connection...
Warning: Failed to create the file ruby-1.9.3-p484.tar.bz2.part: Permission
Warning: denied
0 9806k 0 1002 0 0 22905 0 0:07:18 --:--:-- 0:07:18 23302
curl: (23) Failed writing body (0 != 1002)
There was an error(23).
Checking fallback: http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p484.tar.bz2
Warning: Failed to create the file ruby-1.9.3-p484.tar.bz2.part: Permission
Warning: denied
0 9806k 0 1167 0 0 4300 0 0:38:55 --:--:-- 0:38:55 4290
curl: (23) Failed writing body (0 != 1167)
There was an error(23).
Failed download
There has been an error fetching the ruby interpreter. Halting the installation.
ubuntu#ip-172-31-0-20:/tmp$

Answer 1

Your RVM is installed in /usr/local/rvm - it's often called system installation, this requires that your user ubuntu will be added to rvm group:
rvm group add rvm "$USER"
yes use $USER it will be replaced by your shell with your user name
then log out and log in, ensure with:
id
that your user is in rvm group,
finally just in case update permissions for RVM:
rvm fix-permissions

Answer 2

The solution by #mpasis might not work if you're installing rvm using ubuntu_rvm as by default because of copy+paste it'll be installed as root.
Try installing rvm with without sudo or with curl as explained on rvm.io.