when i finish update to the version a422d67,command the composer update show the error as follow
PHP Fatal error: Uncaught exception 'PharException' with message 'phar "/usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar" has a broken signature' in /usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar:23
Stack trace:
#0 /usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar(23): Phar::mapPhar('composer.phar')
#1 {main}

thrown in /usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar on line 23

Fatal error: Uncaught exception 'PharException' with message 'phar "/usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar" has a broken signature' in /usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar:23
Stack trace:
#0 /usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar(23): Phar::mapPhar('composer.phar')
#1 {main}

thrown in /usr/local/Cellar/composer/1.0.0-alpha9/libexec/composer.phar on line 23

how can i do ??