Here is a sample commandline output for gbd :
[packager@localhost ~]$ gbd
rm -f /home/packager/src/apt/pclinuxos/2010/base/*
genbasedir --flat --bz2only --progress /home/packager/src/apt/pclinuxos/2010 athlon i586 noarch
Components: athlon i586 noarch
Processing pkglists... athlon i586 0004/0004 noarch 0005/0005 [done]
Processing srclists... [done]
Updating component releases... athlon i586 noarch [done]
Creating global release file... [done]
Appending MD5Sum... athlon i586 noarch [done]
All your base are belong to us!!!
Update apt package list? [y/N] y
Please enter root Password:
Get:1 http://ftp.nluug.nl megagames release [503B]
Get:2 http://ftp.nluug.nl pclinuxos/2010 release [2884B]
Fetched 3387B in 5s (572B/s)
Hit http://ftp.nluug.nl megagames/megagames pkglist
Hit http://ftp.nluug.nl megagames/megagames release
Hit http://ftp.nluug.nl pclinuxos/2010/main pkglist
Hit http://ftp.nluug.nl pclinuxos/2010/main release
Hit http://ftp.nluug.nl pclinuxos/2010/updates pkglist
Hit http://ftp.nluug.nl pclinuxos/2010/updates release
Hit http://ftp.nluug.nl pclinuxos/2010/nonfree pkglist
Hit http://ftp.nluug.nl pclinuxos/2010/nonfree release
Hit http://ftp.nluug.nl pclinuxos/2010/kde pkglist
Hit http://ftp.nluug.nl pclinuxos/2010/kde release
Hit http://ftp.nluug.nl pclinuxos/2010/games pkglist
Hit http://ftp.nluug.nl pclinuxos/2010/games release
Hit http://ftp.nluug.nl pclinuxos/2010/xfce4 pkglist
Hit http://ftp.nluug.nl pclinuxos/2010/xfce4 release
Reading Package Lists... Done
Building Dependency Tree... Done
Note that there is a question asked in the middle for which if I answer No, my local repo is not updated.
In the last part, if the earlier answer was Yes, it hits the public mirrors to get the latest repository list. If I do not have an internet connection, then it fails with error.
I want an ability to update only the local repository which is what changes when I package, correct errors, repackage etc.