[Yum] how to update from a local repository

[Francois Massonneau]

Hello,

I've tried to find a solution in the mailing list archive, but I did not 
find the trick that could help me.
I've just upgraded from FedoraCore 2 to FC3, and I used to update my home 
computer (I don't the adsl at home), using my laptop wireless (at work the 
adsl is available).
Using FC2, I run "yum-arch -l ." to create the local repository on my 
laptop, and a yum update from my home computer with the following entries 
in my /etc/yum.conf, worked like a charm.
---------------------
[main]
cachedir=/var/cache/yum
debuglevel=3
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=redhat-release
tolerant=1
exactarch=1
retries=20
[laptop]
name=LocalStuff
baseurl=file:///mnt/celtes5/usr/local/myrepo
----------------------------------

Now, using FC3, I saw yum-arch, was useless, and I have to use createrepo. 
I've tried the following two ways :
createrepo /usr/local/myrepo
and createrepo -u file:///usr/local/myrepo /usr/local/myrepo
Both seems to work.
But on my home computer, when I run a yum update, I have the following error 
message :
[root at celtes2 fm]# yum update
Yum Version: 2.1.11
COMMAND: yum update
Installroot: /
Setting up Update Process
Setting up Repo:  laptop
Baseurl(s) for repo: ['file:///mnt/celtes5/usr/local/myrepo']
repomd.xml                100% |=========================| 1.1 kB    00:00
Setting up Repo:  base
Cannot find a valid baseurl for repo: base

How can I do to make to work as before ? Thank you. Francois