It doesn’t search in your $HOME directory by default, unless you tell it to during the compilation. The default search rules, laid out by the dtool/Config.pp, are:
(1) search the directory named by $PRC_DIR
(2) search the directories on the variable named by $PRC_PATH
(3) search /usr/local/panda/etc
If you wish it to search the directory named by $HOME in addition to the above rules, you could add the following line to your Config.pp file:
#define PRC_DIR_ENVVARS PRC_DIR HOMEDavid