# Cogito Tutorial If It Helps 10 messages from 2005-04-26 to 2005-04-28. Participants: James Purser, Petr Baudis, Alan Chandler, Benjamin Herrenschmidt. Thread: https://gitlist.dev/t/336 ## James Purser, 2005-04-26 20:52 Subject: Cogito Tutorial If It Helps Message-ID: <1114548747.3083.1.camel@kryten> URL: https://gitlist.dev/e/1114548747.3083.1.camel%40kryten ``` I reworked the previous tutorial to take in the changes in the scripts. Will make this a series of tutorials to cover all aspects. Any suggestions or hints or spelling corrections would be most welcome. http://ksit.dynalias.com/articles.php?s_id=46&art_id=41 -- James Purser http://ksit.dynalias.com ``` ## Petr Baudis, 2005-04-26 21:18 Subject: Re: Cogito Tutorial If It Helps Message-ID: <20050426211834.GO13224@pasky.ji.cz> URL: https://gitlist.dev/e/20050426211834.GO13224%40pasky.ji.cz In-Reply-To: <1114548747.3083.1.camel@kryten> ``` Dear diary, on Tue, Apr 26, 2005 at 10:52:27PM CEST, I got a letter where James Purser told me that... > I reworked the previous tutorial to take in the changes in the scripts. > Will make this a series of tutorials to cover all aspects. Any > suggestions or hints or spelling corrections would be most welcome. > > http://ksit.dynalias.com/articles.php?s_id=46&art_id=41 Thanks for writing that! :-) I'd vote for describing the cg-update right near cg-pull, or perhaps even before cg-update, as the primary method; I think it's commonly what people really want to do when they do cg-pull anyway. cg-merge is _not_ like doing cg-diff | cg-patch - that's a dangerous thought, and not true at all. cg-diff | cg-patch will just apply the given diff to your working directory, but it won't record any merging metadata, will often get it very wrong, and you will get to all sorts of other troubles. Just always use cg-merge. And probably pass it -b only when you know what are you doing. Thanks, -- Petr "Pasky" Baudis Stuff: http://pasky.or.cz/ C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor ``` ## James Purser, 2005-04-26 21:36 Subject: Re: Cogito Tutorial If It Helps Message-ID: <1114551403.3083.3.camel@kryten> URL: https://gitlist.dev/e/1114551403.3083.3.camel%40kryten In-Reply-To: <20050426211834.GO13224@pasky.ji.cz> ``` On Wed, 2005-04-27 at 07:18, Petr Baudis wrote: > Dear diary, on Tue, Apr 26, 2005 at 10:52:27PM CEST, I got a letter > where James Purser told me that... > > I reworked the previous tutorial to take in the changes in the scripts. > > Will make this a series of tutorials to cover all aspects. Any > > suggestions or hints or spelling corrections would be most welcome. > > > > http://ksit.dynalias.com/articles.php?s_id=46&art_id=41 > > Thanks for writing that! :-) > > I'd vote for describing the cg-update right near cg-pull, or perhaps > even before cg-update, as the primary method; I think it's commonly what > people really want to do when they do cg-pull anyway. > > cg-merge is _not_ like doing cg-diff | cg-patch - that's a dangerous > thought, and not true at all. cg-diff | cg-patch will just apply the > given diff to your working directory, but it won't record any merging > metadata, will often get it very wrong, and you will get to all sorts of > other troubles. Just always use cg-merge. And probably pass it -b only > when you know what are you doing. > > Thanks, Thanks for that, I've changed it a little to point out that cg-patch should really only be used for small single file patches. -- James Purser http://ksit.dynalias.com ``` ## Petr Baudis, 2005-04-26 21:40 Subject: Re: Cogito Tutorial If It Helps Message-ID: <20050426214038.GP13224@pasky.ji.cz> URL: https://gitlist.dev/e/20050426214038.GP13224%40pasky.ji.cz In-Reply-To: <1114551403.3083.3.camel@kryten> ``` Dear diary, on Tue, Apr 26, 2005 at 11:36:43PM CEST, I got a letter where James Purser told me that... > On Wed, 2005-04-27 at 07:18, Petr Baudis wrote: > > cg-merge is _not_ like doing cg-diff | cg-patch - that's a dangerous > > thought, and not true at all. cg-diff | cg-patch will just apply the > > given diff to your working directory, but it won't record any merging > > metadata, will often get it very wrong, and you will get to all sorts of > > other troubles. Just always use cg-merge. And probably pass it -b only > > when you know what are you doing. > > Thanks for that, I've changed it a little to point out that cg-patch > should really only be used for small single file patches. No, you've missed the point. It isn't the size of the change what matters - cg-patch should handle even huge patches (mostly) fine. What matters is that you just did was not merge. It was applying some patch to your working tree, but not merging branches. So after doing cg-diff | cg-patch several times, you have your working tree full of huge local changes (making it impossible to sensibly cg-merge) and your last commit happenned long ago. Or you commit the cg-patch results, but your commits are wrong, since they don't carry the appropriate merge information. -- Petr "Pasky" Baudis Stuff: http://pasky.or.cz/ C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor ``` ## Alan Chandler, 2005-04-27 18:22 Subject: Re: Cogito Tutorial If It Helps Message-ID: <200504271922.07765.alan@chandlerfamily.org.uk> URL: https://gitlist.dev/e/200504271922.07765.alan%40chandlerfamily.org.uk In-Reply-To: <1114548747.3083.1.camel@kryten> ``` On Tuesday 26 April 2005 21:52, James Purser wrote: > I reworked the previous tutorial to take in the changes in the scripts. > Will make this a series of tutorials to cover all aspects. Any > suggestions or hints or spelling corrections would be most welcome. > > http://ksit.dynalias.com/articles.php?s_id=46&art_id=41 Although I have been reading this mailing list since almost the beginning, I have not had a chance to download and try anything. Using this message as an incentive to start, I started to follow this. However I have run into problems. Let me try and explain. The first part of the tutorial of loading the tarball and building things is fine (should be, its a well trodden mental model) - and actually for me I did not have libcurl3-dev installed the first time - but because I already had the mental model in my mind on this stage it was easy to fit. I then issued the cg-clone command to get a fresh copy of cogito. This is where I think it would be useful to take time-out from the tutorial and explain what I have here. For me at least, if I don't have a mental model of what is happening, I am totally confused. I "think" I understand the git repository with the various content addressable objects. Reading the README file describes that quite well. I assume that is what is stored in the .git subdirectory (although I have yet to find any text that formally says that). Where I am confused is the relationship between what is in the .git subdirectory and the project tree of cogito that sits around it. Obviously I understand that its the latest version of the project as represented by the objects in the repository, but what I don't really understand (and neither your tutorial nor all the explanations of each of the commands in the README really explain it either) is how the various commands adjust the relationship. For instance cg-branch-add seems to add a branch to the repository from a url (I assume it downloads any "blobs" etc that are not already in my local repository and creates a tag that identifies the head of a tree object), but a don't understand how I am supposed see that particular branch as expanded code. (I suspect it might be cg-seek, but I am not really sure - and if it is how do you find out what branch this expanded code is now pointed to?). But what do cg-update and cg-pull do in terms of the uncompressed code sitting in the surrounding directory round the repository, particularly when you perform them on a branch that is not the one that the code refers to. The reason I raise all this, is when I follow through on your tutorial and get to the cg-diff stage I get this xargs: cg-Xdiffdo: No such file or directory And I have absolutely no idea whats wrong or where to start looking. -- Alan Chandler http://www.chandlerfamily.org.uk ``` ## Petr Baudis, 2005-04-27 19:32 Subject: Re: Cogito Tutorial If It Helps Message-ID: <20050427193227.GF22956@pasky.ji.cz> URL: https://gitlist.dev/e/20050427193227.GF22956%40pasky.ji.cz In-Reply-To: <200504271922.07765.alan@chandlerfamily.org.uk> ``` Dear diary, on Wed, Apr 27, 2005 at 08:22:07PM CEST, I got a letter where Alan Chandler told me that... > Where I am confused is the relationship between what is in the .git > subdirectory and the project tree of cogito that sits around it. Obviously I > understand that its the latest version of the project as represented by the > objects in the repository, but what I don't really understand (and neither > your tutorial nor all the explanations of each of the commands in the README > really explain it either) is how the various commands adjust the > relationship. > > For instance cg-branch-add seems to add a branch to the repository from a url > (I assume it downloads any "blobs" etc that are not already in my local > repository and creates a tag that identifies the head of a tree object), but > a don't understand how I am supposed see that particular branch as expanded > code. (I suspect it might be cg-seek, but I am not really sure - and if it > is how do you find out what branch this expanded code is now pointed to?). > But what do cg-update and cg-pull do in terms of the uncompressed code > sitting in the surrounding directory round the repository, particularly when > you perform them on a branch that is not the one that the code refers to. Those commands affect your working tree: cg-cancel Cancels out any modifications in the working tree w.r.t. the last commit cg-merge Merges changes done in another branch to your current branch cg-patch Applies a patch, with regard to special git-specific info generated by cg-diff cg-rm Removed the file from your working tree if it's still around cg-seek Changes your working tree to match some other commit in the database cg-update Potentially brings in changes from a remote branch, and updates your working tree to the latest commit + those changes Those commands affect the objects database: cg-commit cg-pull cg-pull just gets the data from remote objects database to the local objects database; it is the "first part" of what cg-update does cg-update This affects both: cg-merge Not directly, but it can call cg-commit automatically. cg-update > The reason I raise all this, is when I follow through on your tutorial and get > to the cg-diff stage I get this > > xargs: cg-Xdiffdo: No such file or directory > > And I have absolutely no idea whats wrong or where to start looking. You didn't do make install and you don't have the cogito tree in your $PATH. -- Petr "Pasky" Baudis Stuff: http://pasky.or.cz/ C++: an octopus made by nailing extra legs onto a dog. -- Steve Taylor ``` ## Alan Chandler, 2005-04-27 22:15 Subject: Re: Cogito Tutorial If It Helps Message-ID: <200504272315.22939.alan@chandlerfamily.org.uk> URL: https://gitlist.dev/e/200504272315.22939.alan%40chandlerfamily.org.uk In-Reply-To: <20050427193227.GF22956@pasky.ji.cz> ``` On Wednesday 27 April 2005 20:32, Petr Baudis wrote: > Those commands affect your working tree: > > cg-cancel > Cancels out any modifications in the working tree w.r.t. > the last commit > cg-merge > Merges changes done in another branch to your current > branch > cg-patch > Applies a patch, with regard to special git-specific > info generated by cg-diff > cg-rm > Removed the file from your working tree if it's still > around > cg-seek > Changes your working tree to match some other commit in > the database > cg-update > Potentially brings in changes from a remote branch, and > updates your working tree to the latest commit + those > changes > > Those commands affect the objects database: > > cg-commit > cg-pull > cg-pull just gets the data from remote objects database > to the local objects database; it is the "first part" > of what cg-update does > cg-update > > This affects both: > > cg-merge > Not directly, but it can call cg-commit automatically. > cg-update Thanks - that makes things a lot clearer > > > The reason I raise all this, is when I follow through on your tutorial > > and get to the cg-diff stage I get this > > > > xargs: cg-Xdiffdo: No such file or directory > > > > And I have absolutely no idea whats wrong or where to start looking. > > You didn't do make install and you don't have the cogito tree in your > $PATH. I DID do a make install - which put everything in ~/bin (including cg-Xdiffdo) and ~/bin is the first item in my $PATH. -- Alan Chandler http://www.chandlerfamily.org.uk ``` ## Benjamin Herrenschmidt, 2005-04-28 00:48 Subject: Re: Cogito Tutorial If It Helps Message-ID: <1114649337.7112.208.camel@gaston> URL: https://gitlist.dev/e/1114649337.7112.208.camel%40gaston In-Reply-To: <1114548747.3083.1.camel@kryten> ``` On Wed, 2005-04-27 at 06:52 +1000, James Purser wrote: > I reworked the previous tutorial to take in the changes in the scripts. > Will make this a series of tutorials to cover all aspects. Any > suggestions or hints or spelling corrections would be most welcome. > > http://ksit.dynalias.com/articles.php?s_id=46&art_id=41 Hrm... this tutorial is exactly like cogito's own readme as far as I'm concerned : it just makes things even more confusing to me. I must be really stupid, I should stick to hacking the kernel and not try to use userland tools :) Anyway, can you explain what it is all about this branch thing ? I don't understand why in hell you would want linux-2.6 to be a branch of cogito itself ... Ben. ``` ## Benjamin Herrenschmidt, 2005-04-28 00:51 Subject: Re: Cogito Tutorial If It Helps Message-ID: <1114649466.7183.210.camel@gaston> URL: https://gitlist.dev/e/1114649466.7183.210.camel%40gaston In-Reply-To: <1114649337.7112.208.camel@gaston> ``` On Thu, 2005-04-28 at 10:48 +1000, Benjamin Herrenschmidt wrote: > On Wed, 2005-04-27 at 06:52 +1000, James Purser wrote: > > I reworked the previous tutorial to take in the changes in the scripts. > > Will make this a series of tutorials to cover all aspects. Any > > suggestions or hints or spelling corrections would be most welcome. > > > > http://ksit.dynalias.com/articles.php?s_id=46&art_id=41 > > Hrm... this tutorial is exactly like cogito's own readme as far as I'm > concerned : it just makes things even more confusing to me. I must be > really stupid, I should stick to hacking the kernel and not try to use > userland tools :) > > Anyway, can you explain what it is all about this branch thing ? > > I don't understand why in hell you would want linux-2.6 to be a branch > of cogito itself ... Forget it, I must be lacking caffeine this morning, you are adding linus git, not linux-2.6 as a branch which makes a lot more sense... sorry for the noise. Ben. ``` ## Alan Chandler, 2005-04-28 05:40 Subject: Re: Cogito Tutorial If It Helps Message-ID: <200504280640.19543.alan@chandlerfamily.org.uk> URL: https://gitlist.dev/e/200504280640.19543.alan%40chandlerfamily.org.uk In-Reply-To: <200504272315.22939.alan@chandlerfamily.org.uk> ``` On Wednesday 27 April 2005 23:15, Alan Chandler wrote: > On Wednesday 27 April 2005 20:32, Petr Baudis wrote: > > You didn't do make install and you don't have the cogito tree in your > > $PATH. > > I DID do a make install - which put everything in ~/bin (including > cg-Xdiffdo) and ~/bin is the first item in my $PATH. Thanks to James Purser its fixed. I needed the full path to ~/bin rather than just using the ~ in $PATH. -- Alan Chandler http://www.chandlerfamily.org.uk ```