Re: [boost] [git] Mercurial?

Subject: Re: [boost] [git] Mercurial?
From: Rafaël Fourquet (fourquet.d+boost_at_[hidden])
Date: 2012-03-26 00:06:57

>
> Now, I created a master Spirit-3 branch off this that I can
> publish into, say, Github. The purpose is to allow people to
> pull from and push into (those whom I give write access to)
> this.
>
> Wanting to make it modular, I searched around and found
> git filter-branch. Hence, I was able to create a modular
> Spirit-3 branch without the other boost libraries. All is
> well until I did a downstream merge to track the changes
> that's going into the Boost trunk into my Spirit-3 branch.
>
>  boost-trunk (pull)--> spirit3
>
> And hah! It pulls in everything (all boost libraries) again.
>
> So, how do you do what I intend to do? All I want is to have
> this repo structure:
>
>   spirit3
>     boost/spirit
>     libs/spirit
>
> that can do a merge both ways (upstream and downstream
> to and from the boost trunk); needless to say, with all
> the histories intact.
>
> With SVN, it is very easy to extract sub-directories while
> still tracking changes both ways to and from the source.
> In Git, everything seems to be one whole global repository.
> This is one thing I dislike and which SVN has better control
> over: modularity. Sure, you can make many "modular" git
> repositories instead of one big one like boost. But the
> reality is, you don't predict up front how a library is
> modularized. Spirit itself spawned at least 3 libraries
> (Phoenix Wave Fusion) that stand on their own now. At one point,
> in the life of a library, you may want to refactor and decouple
> parts somewhere else. Doing this in Git is not straightforward
> at all, unless I am missing something obviously simple (?).
>

The git-subtree program (at https://github.com/apenwarr/git-subtree,
see the git-subtree.txt file for documentation) seems to be designed
to address this problem (IIUC, I only used it for a basic case),
which is maybe not that straightforward!