Hi,

I want to try to compile Mer on my Macbook Pro, running Snow Leopard.

It's is possibile ?
I looked for a guide to compile Mer without OBS, but it seems impossibile

Compiling Mer w/o OBS... sure you can do that

Can I also check if you mean "compile Mer" or "compile (an application) *for* Mer" ?

I'll assume you meant what you said...

Also, are you trying to
1) build Mer on your Macbook?
2) build Mer as natively as possible in Snow Leopard?

The answer to 1 is probably a Suse or Debian VM and should be a doddle.

The answer to 2 is probably a nervous breakdown

If you meant 2 then we'll start something like this...

OBS is really nothing to do with the actual compiling... it's more to do with setting up the right environment and monitoring the build.

"All" it does is setup a chroot with the build dependencies and eventually invoke "dpkg-buildpackage -b".
It does this in the 'right' order by examining the dependency chains and waiting for one build to succeed before starting the next. Bear in mind this all needs doing inside an ARM emulator (qemu).

Of course a 1-line osc command (from OBS) does all this for you on your local box too (under linux).

You can do it by hand if you're feeling Gentoo-ish

For each of the 200 or so packages:
"Just" download all the build dependencies you need for a specific source package; unpack them into a target directory (running the postinst scripts in the target as needed).
To get some much needed hints you can examine an OBS build log (in fact that's the most sane way to do it unless you really want to manually check the dependencies).

This is why we use OBS

Nb: undoubtedly there are other debian based build tools that will do the job too.

I mean creating a Mer image under OS X, in particular your option 2 :P

So I think that it's time to warm-up virtual box and install a virtual linux for Maemo

PS:
I have a Nokia N800, and I'm waiting to buy a N900
So I'm thinking to use the N800 as a sandbox and play with the hardware, installing Mer or NITdroid or studying how to port an OS to the N800.
Building a Mer, following every step, will be the example part

Sorry for my bad english and thank you for the answer