# Git branch bug 7 messages from 2007-05-05 to 2007-05-06. Participants: Guido Ostkamp, Johannes Schindelin, Daniel Barkalow, Junio C Hamano. Thread: https://gitlist.dev/t/7985 ## Guido Ostkamp, 2007-05-05 16:24 Subject: Git branch bug Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0705051823300.13988%40bianca.dialin.t-online.de ``` Hello, I would like to report the following bug: $ mkdir test $ cd test $ git init Initialized empty Git repository in .git/ $ git branch experimental fatal: Not a valid object name: 'master'. So, it seems it is not possible to create a named branch on an empty repository. I'm not subscribed to the list, so please keep me directly on CC for any reply, thanks. Regards Guido ``` ## Johannes Schindelin, 2007-05-05 16:42 Subject: Re: Git branch bug Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0705051841200.4015%40racer.site In-Reply-To: ``` Hi, On Sat, 5 May 2007, Guido Ostkamp wrote: > $ mkdir test > $ cd test > $ git init > Initialized empty Git repository in .git/ > $ git branch experimental > fatal: Not a valid object name: 'master'. > > So, it seems it is not possible to create a named branch on an empty > repository. Actually, it is not possible to branch from a non-existing branch. So, this is somewhat expected from my POV. Ciao, Dscho ``` ## Daniel Barkalow, 2007-05-05 17:05 Subject: Re: Git branch bug Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0705051253380.28708%40iabervon.org In-Reply-To: ``` On Sat, 5 May 2007, Johannes Schindelin wrote: > Hi, > > On Sat, 5 May 2007, Guido Ostkamp wrote: > > > $ mkdir test > > $ cd test > > $ git init > > Initialized empty Git repository in .git/ > > $ git branch experimental > > fatal: Not a valid object name: 'master'. > > > > So, it seems it is not possible to create a named branch on an empty > > repository. > > Actually, it is not possible to branch from a non-existing branch. So, > this is somewhat expected from my POV. This leaves open the question of how you make your initial commit in a branch that isn't master. I think the answer should be: $ git checkout -b experimental warning: You appear to be on a branch yet to be born. warning: Forcing checkout of HEAD. fatal: just how do you expect me to merge 0 trees? Which should probably be: $ git checkout -b experimental warning: You appear to be on a branch yet to be born. warning: Putting you on a new branch yet to be born. And leaving .git/HEAD pointing to refs/heads/experimental instead of refs/heads/master, with refs/heads/ still empty. $ git branch experimental Should probably give a more informative error message, but branches with no commits that aren't the current branch has no existance at all, so it can't work to create them without switching to them. -Daniel *This .sig left intentionally blank* ``` ## Guido Ostkamp, 2007-05-05 17:44 Subject: Re: Git branch bug Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0705051942550.14963%40bianca.dialin.t-online.de In-Reply-To: ``` > On Sat, 5 May 2007, Guido Ostkamp wrote: > >> $ mkdir test >> $ cd test >> $ git init >> Initialized empty Git repository in .git/ >> $ git branch experimental >> fatal: Not a valid object name: 'master'. >> >> So, it seems it is not possible to create a named branch on an empty >> repository. > > Actually, it is not possible to branch from a non-existing branch. So, > this is somewhat expected from my POV. >From a git beginners point of view, I would expect that the 'master' branch is automatically created when performing the 'git init'. Why is this not the case? Regards Guido ``` ## Johannes Schindelin, 2007-05-05 17:54 Subject: Re: Git branch bug Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0705051954130.4015%40racer.site In-Reply-To: ``` Hi, On Sat, 5 May 2007, Guido Ostkamp wrote: > > On Sat, 5 May 2007, Guido Ostkamp wrote: > > > > > $ mkdir test > > > $ cd test > > > $ git init > > > Initialized empty Git repository in .git/ > > > $ git branch experimental > > > fatal: Not a valid object name: 'master'. > > > > > > So, it seems it is not possible to create a named branch on an empty > > > repository. > > > > Actually, it is not possible to branch from a non-existing branch. So, > > this is somewhat expected from my POV. > > From a git beginners point of view, I would expect that the 'master' > branch is automatically created when performing the 'git init'. Why is > this not the case? Well, one side of the branch _is_ created. But you have to provide initial content, to make it a proper branch, from which you can actually branch off. Having said that, and having read Daniels mail, I agree that this behaviour should be changed, along with the behaviour of "git checkout -b " in a fresh repo. It might be the illogical thing, to allow branching of a yet-to-be-initialised branch, but it does not hurt either. Ciao, Dscho ``` ## Junio C Hamano, 2007-05-06 06:30 Subject: Re: Git branch bug Message-ID: <7vabwih3bd.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vabwih3bd.fsf%40assigned-by-dhcp.cox.net In-Reply-To: ``` Daniel Barkalow writes: > This leaves open the question of how you make your initial commit in a > branch that isn't master. I think the answer should be: > > $ git checkout -b experimental > warning: You appear to be on a branch yet to be born. > warning: Forcing checkout of HEAD. > fatal: just how do you expect me to merge 0 trees? > > Which should probably be: > > $ git checkout -b experimental > warning: You appear to be on a branch yet to be born. > warning: Putting you on a new branch yet to be born. > > And leaving .git/HEAD pointing to refs/heads/experimental instead of > refs/heads/master, with refs/heads/ still empty. While I agree that is probably correct, it would not be useful in real-life that much. When you do not even have 'master', I do not think there is much point of being able to create two useless, yet-to-be-born branches. Also, once you make a commit on 'master', you would not be able to create a new disconnected root with your suggestion alone. I am not convinced that being able to start a disconnected root is useful to begin with, but it is a different matter. We allow fetching and merging from a different repository to cause disconnected roots to exist in a repository anyway, so I do not see any reason to disallow it either. Assuming that the ability to switch to a new yet-to-be-born branch is useful, I think the right thing to do is: - Regardless of your HEAD state, you may want to have a way to create a yet-to-be-born branch and switch to it. Perhaps "git checkout -e new" make HEAD point at refs/heads/new without creating one (I picked -e randomly for "empty"). - When you are on a yet-to-be-born branch, "git checkout -b new" and "git checkout -b new HEAD" makes HEAD point at refs/heads/new without creating one. I happen to consider this a not so useful corner case, but that is to make things consistent. - When you are on a yet-to-be-born branch, "git branch new" and "git branch new HEAD" is a nonsense operation. We should clearly state that it is nonsense (I am agreeing with the last point in your message). ``` ## Daniel Barkalow, 2007-05-06 16:16 Subject: Re: Git branch bug Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0705061141170.28708%40iabervon.org In-Reply-To: <7vabwih3bd.fsf@assigned-by-dhcp.cox.net> ``` On Sat, 5 May 2007, Junio C Hamano wrote: > Daniel Barkalow writes: > > > This leaves open the question of how you make your initial commit in a > > branch that isn't master. I think the answer should be: > > > > $ git checkout -b experimental > > warning: You appear to be on a branch yet to be born. > > warning: Forcing checkout of HEAD. > > fatal: just how do you expect me to merge 0 trees? > > > > Which should probably be: > > > > $ git checkout -b experimental > > warning: You appear to be on a branch yet to be born. > > warning: Putting you on a new branch yet to be born. > > > > And leaving .git/HEAD pointing to refs/heads/experimental instead of > > refs/heads/master, with refs/heads/ still empty. > > While I agree that is probably correct, it would not be useful > in real-life that much. When you do not even have 'master', I > do not think there is much point of being able to create two > useless, yet-to-be-born branches. The point is that you may not want to have a branch named "master", but rather want your first branch to be named something else. Your project could be such that "master" would be a confusing term to use for a default branch. Currently, it's awkward to start a project that avoids that particular name, which is what it seemed to me that the original poster was trying to do. I don't think it's useful to be able to switch to a new yet-to-be-born branch from any other state, but I do think it's useful to be able to choose what the first branch is. -Daniel *This .sig left intentionally blank* ```