Notes on Drush

My drush commands suddenly stopped working -- I have been too lazy to follow the project, so now I have to dig in to find out why.

As it turns out, the drush command object structure seems to have changed since version 3.x, hence this note to self:

/**
 * Matches a commands array, as returned by drush_get_arguments, with the
 * current command table.
 *
 * Note that not all commands may be discoverable at the point-of-call,
 * since Drupal modules can ship commands as well, and they are
 * not available until after bootstrapping.
 *
 * drush_parse_command returns a normalized command descriptor, which
 * is an associative array with the following entries:
 * - callback: name of function to invoke for this command.
 * - callback arguments: an array of arguments to pass to the calback.
 * - description: description of the command.
 * - arguments: an array of arguments that are understood by the command. for help texts.
 * - options: an array of options that are understood by the command. for help texts.
 * - examples: an array of examples that are understood by the command. for help texts.
 * - scope: one of 'system', 'project', 'site'.
 * - bootstrap: drupal bootstrap level (depends on Drupal major version). -1=no_bootstrap.
 * - core: Drupal major version required.
 * - drupal dependencies: drupal modules required for this command.
 * - drush dependencies: other drush command files required for this command (not yet implemented)
 *
 * @example
 *   drush_parse_command();
 *
 */