gistfile1.txt

joe@faultline:~$ rvm upgrade 1.9.2-p290 1.9.3-p0
Are you sure you wish to upgrade from ruby-1.9.2-p290 to     ruby-1.9.3-p0? (Y/n): y
Installing new ruby ruby-1.9.3-p0
Installing Ruby from source to: /Users/joe/.rvm/rubies/ruby-1.9.3-p0, this may take a while depending on your cpu(s)...

ruby-1.9.3-p0 - #fetching 
ruby-1.9.3-p0 - #downloading ruby-1.9.3-p0, this may take a while depending on your connection...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 9330k  100 9330k    0     0   789k      0  0:00:11  0:00:11 --:--:-- 1474k
ruby-1.9.3-p0 - #extracting ruby-1.9.3-p0 to /Users/joe/.rvm/src/ruby-1.9.3-p0
ruby-1.9.3-p0 - #extracted to /Users/joe/.rvm/src/ruby-1.9.3-p0
Fetching yaml-0.1.4.tar.gz to /Users/joe/.rvm/archives
Extracting yaml-0.1.4.tar.gz to /Users/joe/.rvm/src
Configuring yaml in /Users/joe/.rvm/src/yaml-0.1.4.
Compiling yaml in /Users/joe/.rvm/src/yaml-0.1.4.
/Users/joe/.rvm/scripts/functions/utility: line 152: date: command not found
Installing yaml to /Users/joe/.rvm/usr
/Users/joe/.rvm/scripts/functions/utility: line 152: date: command not found
ERROR: Error running 'make install', please read /Users/joe/.rvm/log/ruby-1.9.3-p0/yaml/make.install.log
env: bash: No such file or directory
ruby-1.9.3-p0 - #configuring 
^CERROR: Error running ' ./configure --prefix=/Users/joe/.rvm/rubies/ruby-1.9.3-p0 --enable-shared --disable-install-doc --with-libyaml-dir=/Users/joe/.rvm/usr ', please read /Users/joe/.rvm/log/ruby-1.9.3-p0/configure.log
ERROR: There has been an error while running configure. Halting the installation.
ERROR: Unable to install ruby ruby-1.9.3-p0.         Please install it manually to continue.

currently works perfectly after updating rvm.
(except gems migration..., just use freshly blank gem list)