Git Fatlas

Git ATLAS without the extra fat!

Motivation and Features

Sometimes you just want to check out a tool from a release and modify or fix it. This is to make that easy:

• Go to your project, somewhere under the top-level CMakeLists.txt file

• Run

  git-fatlas-init
  cd athena
  git-fatlas-add PackgeNa<tab> OtherPackage<tab>
  

  (That's right, tab complete!)

• Go back and build your package again.

  Atlas CMake will find the package you just checked out, so there's no need to edit package filters etc.

To remove a package use git-fatlas-remove Path/To/Package.

List of commands

The high-level commands are:

• git-fatlas-init: Clone an Athena repository here. Nothing will be checked out.
• git-fatlas-add: Add a package to the sparse checkout.
• git-fatlas-remove: Remove a package from the sparse checkout.
• git-fatlas-new: Add something from the working tree to the sparse checkout. This is how you should add new packages to the repo. Note that you still need to commit your changes.
• git-fatlas-user-remote-add: add a user remote based on the path you checked out.

Since this is a new package there are still some plumbing commands that you might have to run sometimes.

• git-fatlas-make-package-list: build the package list in the tmp directory, and echo where it's stored. This is only used to make tab complete faster.
• git-fatlas-remake-package-list: force rebuilding the package list. If you add or remove a bunch of things you might have to call this. Hopefully not though.
• git-fatlas-copyright-update: update copyright notices to the current year. Takes an optional argument for the commit / branch / tag you started with, defaults to atlas/master.

For most other commands you can use standard git.

Comparison to other packages

In general this package won't try to hold your hand with git or CMake: it won't auto-generate any files or assume that you'll always want to push to a specific fork. This is a slightly different philosophy from other packages, for example:

• git-atlas: This assumes you want a WorkDir, which includes a package_filters.txt file. This is useful for full Atlas releases, but it can get in the way if you just want to rebuild a few Athena package within another project.

• acm: This is designed to make working with git and CMake more like working with RootCore. It streamlines some common operations when maintaining analysis code, but being built on top of git-atlas it also inherits the confusing bits.

In short, if you prefer git and CMake to whatever ATLAS was using before but find the sparse checkout thing a bit confusing, this package might be useful to you. If you want to abstract away most of the underlying tools, you should use something else.

Installation

• Clone this repo
• Add source git-fatlas.sh to your .bashrc

Examples

1. Working with master

Running the following will checkout <PackageName> from master.

git-fatlas-init
cd athena
git-fatlas-add <PackgeName>

If you want to build standalone changes to Athena, you can then run

git-fatlas-add WorkDir
cd ../build
cmake ../athena/Projects/WorkDir; make

2. Working branches which are not master

As above, but use the -r argument if you want to checkout packages from a branch which is not master.

git-fatlas-init -r <AthenaBranchName>

3. Working with tags

If you need to checkout packages from a tag, you need to use standard git commands. The following will checkout the desired tag in a local branch called <MyNewBranchName> and automatically switch to the new branch.

git-fatlas-init
cd athena
git checkout -b <MyNewBranchName> <AthenaTagName>

4. Working with merge requests

If you need to checkout packages from a merge request, you need to use standard git commands. The following will checkout the desired merge request in a local branch called <MyNewBranchName> and automatically switch to the new branch.

git-fatlas-init
cd athena
git fetch atlas merge-requests/<RequestID>/head:<MyNewBranchName> && git checkout <MyNewBranchName>