I cannot log in after installing MODX Revolution - php

Question

After installing MODX Revolution I cannot log in - just a blank page is displayed. My setup: MODX downloaded from git, PHP 5.3, Apache 2.2, OS ubuntu.
In apache error log I see this message:
[Sun Sep 04 08:03:12 2011] [error] PHP Fatal error: Call to a member
function render() on a non-object in
/var/www/modx/manager/controllers/default/welcome.class.php on line
64 [Sun Sep 04 08:03:12 2011] [error] PHP Stack trace: [Sun Sep 04
08:03:12 2011] [error] PHP 1. {main}()
/var/www/modx/manager/index.php:0 [Sun Sep 04 08:03:12 2011] [error]
PHP 2. modManagerRequest->handleRequest()
/var/www/modx/manager/index.php:71 [Sun Sep 04 08:03:12 2011] [error]
PHP 3. modManagerRequest->prepareResponse()
/var/www/modx/core/model/modx/modmanagerrequest.class.php:124 [Sun
Sep 04 08:03:12 2011] [error] PHP 4.
modManagerResponse->outputContent()
/var/www/modx/core/model/modx/modmanagerrequest.class.php:173 [Sun
Sep 04 08:03:12 2011] [error] PHP 5. modManagerController->render()
/var/www/modx/core/model/modx/modmanagerresponse.class.php:106 [Sun
Sep 04 08:03:12 2011] [error] PHP 6.
WelcomeManagerController->process()
/var/www/modx/core/model/modx/modmanagercontroller.class.php:133

Answer 1

Actually, Paul Graffam is right in the comments, when building from git (either through a clone or download from github), you need to run transport.core.php as well as some other things the first time you do it.
Specific instructions can be found here: http://rtfm.modx.com/display/revolution20/Git+Installation
An alternative if you don't want to go through those steps is to download a nightly build from http://modx.com/download/nightlies/ - you can install them as normal there.
(Realise I'm a bit late to the question, but figured others might stuble across it in the future and there's no answer yet)