Error installing npm

error.log

npm ERR! Error: Failed to mkdir /usr/local: File exists
npm ERR!     at STATCB (/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.73154/package/lib/utils/mkdir-p.js:117:19)
npm ERR!     at cb (/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.73154/package/lib/utils/graceful-fs.js:31:9)

npm_error.log

-> % curl http://npmjs.org/install.sh | sh                                                                                                                                                                      <<<  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current                                 Dload  Upload   Total   Spent    Left  Speed100  3902  100  3902    0     0  20825      0 --:--:-- --:--:-- --:--:-- 30015fetching: http://registry.npmjs.org/npm/-/npm-1.0.15.tgz
0.5.2-pre
1.0.15
prefix=/usr/local
altprefix=/usr/local/Cellar/node/0.5.1

This script will find and eliminate any shims, symbolic
links, and other cruft that was installed by npm 0.x.
Is this OK? enter 'yes' or 'no' yesAll clean!
! [ -d .git ] || git submodule update --init
node cli.js cache clean
node cli.js rm npm -g -f --loglevel error
node cli.js install -g -f
npm ERR! Error: Failed to mkdir /usr/local: File exists
npm ERR!     at STATCB (/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/lib/utils/mkdir-p.js:117:19)
npm ERR!     at cb (/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/lib/utils/graceful-fs.js:31:9)
npm ERR! Report this *entire* log at:
npm ERR!     <http://github.com/isaacs/npm/issues>
npm ERR! or email it to:
npm ERR!     <[email protected]>
npm ERR! 
npm ERR! System Darwin 10.8.0
npm ERR! command "node" "/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/cli.js" "install" "-g" "-f"
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/npm-debug.log
npm not ok
make: *** [install] Error 1
npm WARN Not installed in /usr/local/lib/node_modules npm
npm ERR! Error: Failed to mkdir /usr/local: File exists
npm ERR!     at STATCB (/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/lib/utils/mkdir-p.js:117:19)
npm ERR!     at cb (/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/lib/utils/graceful-fs.js:31:9)
npm ERR! Report this *entire* log at:
npm ERR!     <http://github.com/isaacs/npm/issues>
npm ERR! or email it to:
npm ERR!     <[email protected]>
npm ERR! 
npm ERR! System Darwin 10.8.0
npm ERR! command "/usr/local/bin/node" "/private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/cli.js" "install" "." "--force" "--global"
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /private/var/folders/1i/1iBDWfZ0FcS+Cwr4gRZ7GU+++TM/-Tmp-/npm.67502/package/npm-debug.log
npm not ok
It failed

rebuild.log

* installing build/default/config.h as /usr/local/Cellar/node/0.5.1/include/node/config.h
* installing build/default/tools/nodejs.pc as /usr/local/Cellar/node/0.5.1/lib/pkgconfig/nodejs.pc
* installing build/default/node as /usr/local/Cellar/node/0.5.1/bin/node
* installing build/debug/node_g as /usr/local/Cellar/node/0.5.1/bin/node_g
* installing build/default/src/node_config.h as /usr/local/Cellar/node/0.5.1/include/node/node_config.h
Waf: Leaving directory `/Users/c/src/node/build'
'install' finished successfully (10m56.621s)