Re: [boost] Git: maintaining super-project

Andrey Semashev writes:

On Wed, Dec 4, 2013 at 12:06 PM, Vladimir Prus wrote:

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On 04.12.2013 11:32, Andrey Semashev wrote:

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I just checked out the super-project:

git clone --recursive http://github.com/boostorg/boost.git modular-boost

It actually said:

Submodule path 'libs/program_options': checked out 'fb4f36f3eecbef1e3b4ace5b263e01d56e42d5c7'

But after these commands I saw the newer revisions:

cd modular-boost/libs/program_options git checkout master Switched to branch 'master'

git log -1 commit 9d7c9875265ec7fec03aabf18e3d53c3e5e1a46c Author: Vladimir Prus Date: Wed Dec 4 09:17:17 2013 +0400

Remove tabs.

I'm not sure what the "Submodule" line means, but it seems the repository is cloned with the newer revisions.

man git-submodule says that the submodule involves something called "gitlink", which refers to the particular revision. I don't know what this is but is it possible to specify HEAD instead of the specific revisions in gitlinks?

It's not possible. Git submodules were purposely designed to only let you link to a specific revision. This is A Good Thing and different from how svn:externals work. The reason for fixed revision links is that a particular commit in the super project is then a snapshot of the entire source tree, submodules and everything. If you could link to a submodule HEAD it would never be possible to get a stable snapshot of superproject commit blah023blah034blah093blah because the source of the submodule may have changed since blah023blah034blah093blah was committed. In short, a dependency nightmare. Git submodules make it very explicit what was intended to link to what. If you want to change the linkage you have to do it _explicitly_ by committing an updated submodule link. That way noone is left confused about what the commit author really intended. Yes, this confused me horribly when I started using git too. Now I can't imagine why I ever wanted it otherwise. Alex -- Swish - Easy SFTP for Windows Explorer (http://www.swish-sftp.org)