rvm fails to install ruby binary with curl error

gistfile1.txt

08:47:28 [bfults@austin] ~$ rvm info

1.8:

  system:
    uname:       "Darwin austin 10.4.0 Darwin Kernel Version 10.4.0: Fri Apr 23 18:28:53 PDT 2010; root:xnu-1504.7.4~1/RELEASE_I386 i386"
    bash:        "/bin/bash => GNU bash, version 3.2.48(1)-release (x86_64-apple-darwin10.0)"
    zsh:         "/bin/zsh => zsh 4.3.9 (i386-apple-darwin10.0)"

  rvm:
    version:      "rvm 1.0.21 by Wayne E. Seguin (wayneeseguin@gmail.com) [http://rvm.beginrescueend.com/]"

  ruby:
    interpreter:  "ruby"
    version:      "1.8.7"
    date:         "2009-06-12"
    platform:     "universal-darwin10.0"
    patchlevel:   "2009-06-12 patchlevel 174"
    full_version: "ruby 1.8.7 (2009-06-12 patchlevel 174) [universal-darwin10.0]"

  homes:
    gem:          "/usr/local/Cellar/gems/1.8"
    ruby:         "not set"

  binaries:
    ruby:         "/usr/bin/ruby"
    irb:          "/usr/bin/irb"
    gem:          "/usr/bin/gem"
    rake:         "/usr/local/bin/rake"

  environment:
    PATH:         "/Users/bfults/Sites/jekyll/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/opt/local/bin:/Users/bfults/bin:/Users/bfults/.rvm/bin:/Users/bfults/.rvm/bin"
    GEM_HOME:     "/usr/local/Cellar/gems/1.8"
    GEM_PATH:     ""
    BUNDLE_PATH:  ""
    MY_RUBY_HOME: ""
    IRBRC:        ""
    RUBYOPT:      ""
    gemset:       ""


08:48:08 [bfults@austin] ~$ rvm install 1.8
/Users/bfults/.rvm/rubies/ruby-1.8, this may take a while depending on your cpu(s)...

ruby-1.8 - #fetching 
ruby-1.8 - #downloading ruby-1.8, this may take a while depending on your connection...

curl: (3) <url> malformed
There was an error, please check /Users/bfults/.rvm/log/ruby-1.8/*.error.log. Next we'll try to fetch via http.

curl: (3) <url> malformed
There was an error, please check /Users/bfults/.rvm/log/ruby-1.8/*.error.log
There has been an error while trying to fetch the source.           
Halting the installation.
There has been an error fetching the ruby interpreter. Halting the installation.
08:48:12 [bfults@austin] ~$ ls -l /Users/bfults/.rvm/log/ruby-1.8/*.error.log
ls: /Users/bfults/.rvm/log/ruby-1.8/*.error.log: No such file or directory

Solution: 1.8 isn't a valid ruby version. rvm install 1.8.7 works fine, as does 1.9.2 etc.