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### 3.11 Using GNU Arch

#### 3.11.1 About GNU Arch

There is no CVS or SVN repository for Liquid War 6. Instead, a GNU Arch repository is used to follow the different versions. Read the GNU Arch tutorial to learn how Arch works. Note that there are many other source control managers available, some of which provide functionnalities similar to GNU Arch / tla. GNU Arch has been chosen for Liquid War 6 because:

- it is Free Software,
- it is not limited to per-file commits like CVS, and supports atomic commits involving several files,
- it is distributed,
- it enables developpers to sign each of their contributions,
- it was already available back in 2005.

#### 3.11.2 Getting the latest version from the repository

The repository for Liquid War 6 is accessible on http://arch.savannah.gnu.org/archives/liquidwar6. This is a read-only access, but with the distributed nature of GNU Arch, it still allows you to keep track of your own changes, and submit patches. Accessing it in read/write mode with sftp requires a Savannah account and special rights on the Liquid War 6 project.

Here are typicall commands one can use to get Liquid War 6 source from the GNU Arch repository:

         tla register-archive http://arch.savannah.gnu.org/archives/liquidwar6
         tla get -A liquidwar6@sv.gnu.org liquidwar6--beta

All the patches in the archive are signed with GnuPG, so you can check their authenticity with my public key.

You might need to edit your `$HOME/.arch-params/signing/=default.check` file and put the following text in it:

         tla-gpg-check gpg_command="gpg --verify-files -"

#### 3.11.3 Setting up your own arch repository

This section is for those who want to hack the game and set up their own repositories. This will enable you to keep track of your patches, package them, and help the core maintainer merging them in the main repository.

You can introduce yourself and create a repository by issuing commands like:

You can introduce yourself and create a repository by issuing commands like:

         tla my-id me@home.net
         tla register-archive me@home.net--2008 /home/me/tla-archives

Then, you can get create your own repository, with a command like:

         tla tag -S liquidwar6@sv.gnu.org/liquidwar6--beta--0.1 me@home.net--2008/liquidwar6--beta--0.4

The idea is that you create, locally, a depot which has a name that matches the name on savannah (this is for convenience, you could technically give it any name...) and indicate that they represent, today, the same thing.

You can get a working copy of your depot with the command:

         tla get me@home.net--2008/liquidwar6--beta--0.4

This will create a complete source tree, which you are free to modify, this is where you should hack.

#### 3.11.4 Synchronizing your repository with upstream releases

To synchronize yourself with upstream developments, go into your copy (the directory created by `tla get`) and type:

         tla star-merge liquidwar6@sv.gnu.org/liquidwar6--beta--0.1

This will apply locally all the changes that happened since the last synchronization. Of course this is one way to work, you can decide to cherry pick patches and such stuff, but for most dayly uses, a good'ol `star-merge` is fine.

Not that `star-merge` will only apply patches on your working copy, not on your repository. The only way to actually commit the modifications on the repository is to use the `commit` command.

#### 3.11.5 Submitting patches

When using Arch, you can of course still send patches created with `diff`, or even send updated files directly, the way you would without revision control.

But it can be more convenient to either

- Send the patches stored in the depot (`/home/me/tla-archives` in our example).
- Make patches using `tla mkpatch`.

Here's an example of an `mkpatch` command, and which will compute the differences between a previous `liquidwar6--beta--0.4--patch-2` snapshot and a not yet commited latest version:

         tla mkpatch {arch}/++pristine-trees/unlocked/liquidwar6/liquidwar6--beta/liquidwar6--beta--0.4/me@home.net--2006/liquidwar6--beta--0.4--patch-2 . my-patch

This will create a `my-patch` directory, which can be gzipped and sent by mail.

#### 3.11.6 Recover from broken lock

Sometimes, when signing a patch, you might enter the wrong passphrase several times, or you might press CTRL+D inadvertantly. In that case, tla will be in a half-broken state, telling you it can't acquire revision lock... A quick workarround for this is to go to the depot, find the latest patch, and in this repository, create the following folders:

         ++revision-lock/+contents

Both are directories, note the two ++ and the single +. the `+contents` directory can be empty. Once you've done this, try to re-commit.