Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
Hey, On Nov 11, 2007 10:34 PM, Jim Fulton [EMAIL PROTECTED] wrote: On Nov 11, 2007, at 2:06 AM, Martijn Faassen wrote: [snip] This breaks a fundamental assumption for releases. When I release something, I expect it to work tomorrow, next month, and next year. If you want this, then you can't rely on the KGS. When releasing our applications, we don't rely on a KGS. We fix all of the versions we're using. IMO, the KGS shouldn't try to solve this problem. A KGS should be helpful for developers and development frameworks. A KGS will be more useful if the quality remains high. A KGS is similar to a traditional monolithic release. After all, bug fix Zope releases have been known to break applications too. I got completely confused by your answers you gave previously: you were talking about feature releases, but of what? Basically here you say that KGS replaces a monolithic release of Zope 3. I see KGS as useful for the developers of Zope 3 classic. I see KGS as a useful source of tested lists of versions where they are related to Zope 3. With code, we know that history, and branches, and so on, are important. We use Subversion. With KGS we only have an ongoing trunk. I'm not sure why you keep saying trunk. I'm not sure if you are being imprecise, or if I'm missing something. There's no reason a KGS couldn't be managed with a revision control system. That might be a very good idea. I say this as this is the impression I get from it. Saying that a KGS could be managed with a revision control system is nice, but can it now? How complicated would that make it? Does it make sense to maintain this information externally to the packages? [snip] There are some fundamental problems with external lists or indexes: * we need to know about the dependency of dependencies, even if we never use them directly. Information hiding is broken. I'm not sure how this is a problem with version lists (external or otherwise) or indexes. Dependencies of dependencies itself isn't a problem, as this information is still in packages themselves. The versions of dependencies isn't, and this is a problem, because I don't *want* to know about dependencies of dependencies, or their versions. I don't want to have to care. The packages themselves should know this. The story for beginners wouldn't be good enough, as they'd need to know too. With ZCML we're finally resolving this by putting this dependency structure in ZCML. Not ideal, but at least when you include package X which needs Y which needs Z, you don't need to manually include the ZCML of Y and Z anymore. Now with package dependencies and versioning, I need to make decisions on the versions of Y and Z, while I just care about using X. I don't want to know this stuff. A beginner can of course, if he's lucky, interact with an index like KGS that makes decisions for them. That works until they need a different version or different package than what is maintained in the index. In that case, they don't want anything external to make the decisions. The basic thing I'd like is to just to ask the package: give me the versions *you* think you can work with. If I'm tracking this package in subversion or upgrade to a new release of the package, this list of best versions might change, too. I don't want to have to know, just like I don't want to have to know about the implementation details of a package. Dependencies and the versions of such are an implementation detail. One I might on occasion like to override, just like I sometimes need to override the implementation details of a class by subclassing, but that should be further along the curve, not immediate. I think it would be reasonable for packages higher up in the dependency tree to have the ability to override version decisions made by packages lower down (as long as there aren't any conflicts within the structure). In these case these package explicitly decide to take over responsibility. * a single list will never do it. We intend to have many different applications that may depend on different versions of packages. Grok may need a newer zope.publication than your application does. A Grok extension may need an even newer version than Grok does. We'll be baking endless amounts of lists this way. I think each application will need to come up with a version list for each of it's releases. In development, an application can use an index or external version list as a starting point. For example, I see a KGS being useful as a (fairly) stable baseline for development. When an application is ready for release, it should fix it's versions. I've tried to make this easy to do with buildout. When you're preparing to make a release, run buildout in verbose mode (-v) It will print out the versions it picked in a format that is easily turned into a version list. Sure, I know about all this. I just am saying that this doesn't do enough. During development I decide I want to
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
Hey, On Nov 12, 2007 12:02 AM, Stephan Richter [EMAIL PROTECTED] wrote: [snip] Like Linux distributions, there will be a KGS for every Zope 3 release. I have already requested a new directory called zope-dev where new feature releases can be tested. Okay, I didn't understand that KGS is replacing the monolithic release story for Zope 3. That's fine as far as it goes. I was focused on the ability that eggs give us for packages to move at different speeds of evolution, and the desire to pick those eggs that we prefer in our applications. If you don't need that, then KGS is basically Zope 3 release + a few features. [snip] We intend to let packages move at different feature-release speeds, and we can't have a KGS for each package. You do not need to have a single KGS for every package. But believing that we can just randomly make new feature releases that work with the rest of the world is naive at best. We have seen already what happens, if everyone uses their own set of versions and packages. Clearly things didn't work in the past. You can't just throw random versions of eggs together. We couldn't do anything better, as the information about what worked together was missing. KGS adds that information back, and that's great. But the information is external to the actual packages. This has drawbacks. I'm saying that if we add this information in the packages internally, we'll be better off, as historical versions and future versions can work. The reuse story is improved. You can make your own selection of versions and have a decent chance it will work together. A development KGS will be used to test new feature releases. What KGS doesn't have is history. Yes, it does. Why do you think I manage the controlled-packages.cfg file in SVN? And in SVN, I do not create branches and tags without a reason. Okay, that's a history. It's a history external to the packages, while the packages have their own history. It's also a global history, while packages can evolve independently. Development decisions of a package's development can change dependency information. It therefore seems natural to me that this information is maintained next to the package. If it's not, and zope.component starts to rely on a newer version of zope.interface, I'd need to maintain this centrally with KGS. We introduce a new monolithic structure where we just removed it. We add back explicitly what was there implicitly: an SVN trunk of Zope 3 maintaining versions that all work together. That's fine to retain the features Zope 3 development had, but I thought the point of splitting Zope 3 up was to be able to forget about the SVN trunk of Zope 3 and just worry about what's right for zope.component. [snip] With Grok, we use an external versions list. We can use this to solve the above problem. We basically take snapshots of what is in KGS. This allows us to maintain some history, though it isn't ideal either, as it's quite a bit of overhead. How is this overhead? Besides releasing Grok, we also need to maintain snapshots of what is in KGS, make such changes as are needed, and publish them. Previously we just released new versions of Grok. That's increased maintenance and release overhead I'd like to get rid of again. If I build an application or framework on top of Grok, I will need to maintain yet another external list for the extra packages of this application, fixing those versions. Why? I don't follow that? Because these packages may be of different versions that in KGS, or may not be managed by KGS altogether. So, while annoying, that is somewhat manageable. Now imagine I want to use a completely separate Python library with my Grok application. This python library has dependencies itself again. This means I will need to know about versions of those dependencies as well, and fix them into my application's list. Yes. I see this as an advantage. Version specifications in `setup.py` usually contain ranges of allowed versions. What happens if one release in the range does not work? Then you make false promises. The only way to avoid this would be by specifying all allowed versions exactly, which makes no sense. That's true. Where I'd like to specify this is as near as possible to where I make the decision to fix these versions. In case of an application, that may be the application. Often that's not the case though: in the case of a library that uses these packages, I'd like it to be the library, and in case of a framework, I'd like it to be the framework. When I develop an application at most I'd like to get the warning: these packages still don't have fixed versions. I'd prefer that list to be empty. There are some fundamental problems with external lists or indexes: * we need to know about the dependency of dependencies, even if we never use them directly. Information hiding is broken. This is a requirement not a problem statement. I don't understand Information hiding
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Nov 11, 2007, at 6:34 PM, Stephan Richter wrote: On Sunday 11 November 2007, Jim Fulton wrote: This breaks a fundamental assumption for releases. When I release something, I expect it to work tomorrow, next month, and next year. If you want this, then you can't rely on the KGS. When releasing our applications, we don't rely on a KGS. We fix all of the versions we're using. IMO, the KGS shouldn't try to solve this problem. A KGS should be helpful for developers and development frameworks. A KGS will be more useful if the quality remains high. A KGS is similar to a traditional monolithic release. After all, bug fix Zope releases have been known to break applications too. I really hope you will use the KGS as a starting point somewhen for your internal applications as well. :-) (Note that you can now override versions using the new extends feature that I shamelessly copied from buildout.) And I am not saying this to promote the KGS. I have a concrete example. Probably as part of a project, Benji did some development on zope.testbrowser. He fixed the versions of all dependencies in buildout.cfg. However, those versions were a version sub-graph of a ZC internal dependency graph that I do not have access to. It was also already pretty outdated referring to dev and alpha releases. So while testbrowser might be working with those dependency versions, it might still be broken for me, because I have a totally different dependency graph. The worst scenario, which luckily has not happened yet, is that we fix things back and forth because of different dependency graphs. I thus propose that all packages in svn.zope.org should use a KGS for testing, because it is a fully public dependency graph. I am not sure whether it should be the latest stable KGS or the development KGS or whatever. Time will provide an answer. I think you make a good point. +1 on using *some* KGS. Jim -- Jim Fulton Zope Corporation ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Monday 12 November 2007, Jim Fulton wrote: I thus propose that all packages in svn.zope.org should use a KGS for testing, because it is a fully public dependency graph. I am not sure whether it should be the latest stable KGS or the development KGS or whatever. Time will provide an answer. I think you make a good point. +1 on using *some* KGS. Since we only have the Zope 3.4 KGS now, I think it would be the best one to use now. :-) The easiest way to do this is to add the following line to the buildout section of the package's `buildout.cfg` file: index = http://download.zope.org/zope3.4 (I know you know that Jim; it is for the benefit of people reading this mail. ;-) Regards, Stephan -- Stephan Richter CBU Physics Chemistry (B.S.) / Tufts Physics (Ph.D. student) Web2k - Web Software Design, Development and Training ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
Stephan Richter wrote: The easiest way to do this is to add the following line to the buildout section of the package's `buildout.cfg` file: index = http://download.zope.org/zope3.4 (I know you know that Jim; it is for the benefit of people reading this mail. ;-) I've been trying to follow this whole thread but it's been pretty high volume so apologies if I've missed something... If I specify index as above, how do I get other packages which may not appear in that index? cheers, Chris -- Simplistix - Content Management, Zope Python Consulting - http://www.simplistix.co.uk ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Nov 11, 2007 8:06 AM, Martijn Faassen [EMAIL PROTECTED] wrote: I therefore still believe that version dependency information should move out of external indexes and into packages. This is at least the intuitive place for this information. My application requires Grok 0.11, which requires zope 3.4.0b2 which then would be a package that doesn't contain any code, just requirements of eggs that in turn has requirements of their own. I'm not even sure this *is* different from how the unices does it, but it just seems the obvious way of doing it. I would be interested in knowing if this has drawbacks. -- Lennart Regebro: Zope and Plone consulting. http://www.colliberty.com/ +33 661 58 14 64 ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
Previously Martijn Faassen wrote: People have been saying that since Linux distributions use external indexes, we should too, as we are dealing with the same problem as Linux distributions. While the problem is similar, I think the nature of development makes our problems, and therefore our solutions, quite different from the way distributions do it. How are we different? We have many, many different small distributions (package + dependencies) that can be combined. We have such a small distribution for each application. We have such a small distribution for each extension. Not just that. We have such a small distribution for each *release* of an application. We have such a small distribution for each *release* of an extension. I therefore still believe that version dependency information should move out of external indexes and into packages. Unless I'm missing something that is exactly what Linux distributions are doing. Each package has its own list of dependencies and conflicts (just as important). When a package is uploaded to a distribution archive that information is copied out of the package and included in the distribution index. That is important since it allows you to grab the index and calculate the whole dependency graph without having to download packages. You can know in advance if something is installable without having to download dozens of pacakges and only then discovering that it will never work. Linux package managers can also handle multiple distributions. If you look at apt for example it can handle as many distributions as you want. You can set priorities for them at distribution-scale (ie always prefer packages from distribution X), at release scale (ie always prefer packages from release Y even if release Z has a newer version) or package scale (package A has to come from distribution X). This is extremely common. If you install a Debian or Ubunutu machine you will always use two distributions: the one for the release, which will never change, and one with security fixes for just that release. Often you will also configure distributions with specific backports (needed because Debian releases are far apart) or for specific products (for your Enlightement 17 snapshot for example which Debian does not have). The terminolpgy is slightly different (archive versus index, package versus egg, depends versus requires, enlightenment versus grok, etc.) but the problem is still the same. Wichert. -- Wichert Akkerman [EMAIL PROTECTED]It is simple to make things. http://www.wiggy.net/ It is hard to make things simple. ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Nov 11, 2007, at 2:06 AM, Martijn Faassen wrote: Hi there, I've been doing some more thinking about external version indexes (like Grok's versions.cfg on a URL, and like KGS) and why they won't solve all our problems. I have a new way to express it, so let me try it out on you all. What KGS solves is that it allows the ongoing development and testing of an integrated Zope 3. I see it addressing a more general problem of having a known good combination of components that work together. There's nothing Zope 3 specific about this. That is, there's a Zope 3 'trunk' of versions that keeps being updated as there are bugfix releases. That's not how I see it. As I've said before, I would model this on linux distributions, where each feature release has a repository of packages for that release, including bug fixes. I'm not sure what happens as soon as someone wants to make a new feature release of any package. They make a new release. At some point, someone will make a new KGS that incorporates this. Presumably they end up in KGS too. After all, we won't have a single Zope 3.4 and then a single Zope 3.5 for which we can create a new KGS. Why not? I would expect that there would be Zope 3.4 and Zope 3.5 KGSs. There might be additional KGSs that include some of the same components. Anyone can assemble a KGS if they think that in doing so, they can add value. We intend to let packages move at different feature-release speeds, and we can't have a KGS for each package. Of course not. Another problem KGS can solve is to add some release hygiene to the cheeseshop: do not remove old releases or overwrite them. I don't really understand this. Maybe you mean that a KGS can be a better alternative to the cheeseshop. I can certainly see that. What KGS doesn't have is history. When I release an application or framework and I used KGS to make sure that all my versions were correct, it will work on the day of release. As soon as enough bugfix (or feature) releases make it to KGS, something will inevitably break. We've seen innocuous changes breaking code a lot of times, so we can't pretend that never happens. It *will* happen. Yup. Which is why you should record versions you use. This breaks a fundamental assumption for releases. When I release something, I expect it to work tomorrow, next month, and next year. If you want this, then you can't rely on the KGS. When releasing our applications, we don't rely on a KGS. We fix all of the versions we're using. IMO, the KGS shouldn't try to solve this problem. A KGS should be helpful for developers and development frameworks. A KGS will be more useful if the quality remains high. A KGS is similar to a traditional monolithic release. After all, bug fix Zope releases have been known to break applications too. With code, we know that history, and branches, and so on, are important. We use Subversion. With KGS we only have an ongoing trunk. I'm not sure why you keep saying trunk. I'm not sure if you are being imprecise, or if I'm missing something. There's no reason a KGS couldn't be managed with a revision control system. That might be a very good idea. With Grok, we use an external versions list. We can use this to solve the above problem. We basically take snapshots of what is in KGS. This allows us to maintain some history, though it isn't ideal either, as it's quite a bit of overhead. Yup. I think both KGSs and version lists are valid approaches. Each has different strengths and weaknesses. If I build an application or framework on top of Grok, I will need to maintain yet another external list for the extra packages of this application, fixing those versions. We could probably even use the extends feature of buildout to have this list point at Grok's list so we have to repeat ourselves less should we want to build something on top of *that* application or framework again. Yup. So, while annoying, that is somewhat manageable. Now imagine I want to use a completely separate Python library with my Grok application. This python library has dependencies itself again. This means I will need to know about versions of those dependencies as well, and fix them into my application's list. Yes There are some fundamental problems with external lists or indexes: * we need to know about the dependency of dependencies, even if we never use them directly. Information hiding is broken. I'm not sure how this is a problem with version lists (external or otherwise) or indexes. * a single list will never do it. We intend to have many different applications that may depend on different versions of packages. Grok may need a newer zope.publication than your application does. A Grok extension may need an even newer version than Grok does. We'll be baking endless amounts of lists this way. I think each application will need to
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Sunday 11 November 2007, Lennart Regebro wrote: On Nov 11, 2007 8:06 AM, Martijn Faassen [EMAIL PROTECTED] wrote: I therefore still believe that version dependency information should move out of external indexes and into packages. This is at least the intuitive place for this information. My application requires Grok 0.11, which requires zope 3.4.0b2 which then would be a package that doesn't contain any code, just requirements of eggs that in turn has requirements of their own. I'm not even sure this *is* different from how the unices does it, but it just seems the obvious way of doing it. I would be interested in knowing if this has drawbacks. Meta-eggs are considered a bad idea in the Python world. I originally wanted to create a meta-egg, but Jim convinced my to use a different approach; hence the index. Regards, Stephan -- Stephan Richter CBU Physics Chemistry (B.S.) / Tufts Physics (Ph.D. student) Web2k - Web Software Design, Development and Training ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Nov 11, 2007, at 6:11 PM, Stephan Richter wrote: On Sunday 11 November 2007, Lennart Regebro wrote: On Nov 11, 2007 8:06 AM, Martijn Faassen [EMAIL PROTECTED] wrote: I therefore still believe that version dependency information should move out of external indexes and into packages. This is at least the intuitive place for this information. My application requires Grok 0.11, which requires zope 3.4.0b2 which then would be a package that doesn't contain any code, just requirements of eggs that in turn has requirements of their own. I'm not even sure this *is* different from how the unices does it, but it just seems the obvious way of doing it. I would be interested in knowing if this has drawbacks. Meta-eggs are considered a bad idea in the Python world. I originally wanted to create a meta-egg, but Jim convinced my to use a different approach; hence the index. Meta eggs aren't a bad or a good idea by themselves. They are a good solution to some problems and a bad (or less good) solution to others. IMO, meta eggs are a good way to fix versions in *applications*. (I think buildout's version-specification mechanism is another good approach, with certain advantages and disadvantages). I think a package repository, of which a KGS is an example, is a good way to provide access to a collection of packages known to work together -- especially as it provides a nice way to manage bug fixes. I think Zope 3 is better served by a well-managed repository, because Zope 3 is a platform, not an application. IMO, a well-managed KGS (set of KGS releases) will serve the community of developers who use Zope better than a rigid version specification. Jim -- Jim Fulton Zope Corporation ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] why external version indexes don't fulfill all use cases for development
On Sunday 11 November 2007, Jim Fulton wrote: This breaks a fundamental assumption for releases. When I release something, I expect it to work tomorrow, next month, and next year. If you want this, then you can't rely on the KGS. When releasing our applications, we don't rely on a KGS. We fix all of the versions we're using. IMO, the KGS shouldn't try to solve this problem. A KGS should be helpful for developers and development frameworks. A KGS will be more useful if the quality remains high. A KGS is similar to a traditional monolithic release. After all, bug fix Zope releases have been known to break applications too. I really hope you will use the KGS as a starting point somewhen for your internal applications as well. :-) (Note that you can now override versions using the new extends feature that I shamelessly copied from buildout.) And I am not saying this to promote the KGS. I have a concrete example. Probably as part of a project, Benji did some development on zope.testbrowser. He fixed the versions of all dependencies in buildout.cfg. However, those versions were a version sub-graph of a ZC internal dependency graph that I do not have access to. It was also already pretty outdated referring to dev and alpha releases. So while testbrowser might be working with those dependency versions, it might still be broken for me, because I have a totally different dependency graph. The worst scenario, which luckily has not happened yet, is that we fix things back and forth because of different dependency graphs. I thus propose that all packages in svn.zope.org should use a KGS for testing, because it is a fully public dependency graph. I am not sure whether it should be the latest stable KGS or the development KGS or whatever. Time will provide an answer. BTW, Benji wanted me to bring this issue up on the mailing list already, so I fulfilled my commitment now. :-) Regards, Stephan -- Stephan Richter CBU Physics Chemistry (B.S.) / Tufts Physics (Ph.D. student) Web2k - Web Software Design, Development and Training ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
[Zope-dev] why external version indexes don't fulfill all use cases for development
Hi there, I've been doing some more thinking about external version indexes (like Grok's versions.cfg on a URL, and like KGS) and why they won't solve all our problems. I have a new way to express it, so let me try it out on you all. What KGS solves is that it allows the ongoing development and testing of an integrated Zope 3. That is, there's a Zope 3 'trunk' of versions that keeps being updated as there are bugfix releases. I'm not sure what happens as soon as someone wants to make a new feature release of any package. Presumably they end up in KGS too. After all, we won't have a single Zope 3.4 and then a single Zope 3.5 for which we can create a new KGS. We intend to let packages move at different feature-release speeds, and we can't have a KGS for each package. Another problem KGS can solve is to add some release hygiene to the cheeseshop: do not remove old releases or overwrite them. What KGS doesn't have is history. When I release an application or framework and I used KGS to make sure that all my versions were correct, it will work on the day of release. As soon as enough bugfix (or feature) releases make it to KGS, something will inevitably break. We've seen innocuous changes breaking code a lot of times, so we can't pretend that never happens. It *will* happen. This breaks a fundamental assumption for releases. When I release something, I expect it to work tomorrow, next month, and next year. With code, we know that history, and branches, and so on, are important. We use Subversion. With KGS we only have an ongoing trunk. With Grok, we use an external versions list. We can use this to solve the above problem. We basically take snapshots of what is in KGS. This allows us to maintain some history, though it isn't ideal either, as it's quite a bit of overhead. If I build an application or framework on top of Grok, I will need to maintain yet another external list for the extra packages of this application, fixing those versions. We could probably even use the extends feature of buildout to have this list point at Grok's list so we have to repeat ourselves less should we want to build something on top of *that* application or framework again. So, while annoying, that is somewhat manageable. Now imagine I want to use a completely separate Python library with my Grok application. This python library has dependencies itself again. This means I will need to know about versions of those dependencies as well, and fix them into my application's list. There are some fundamental problems with external lists or indexes: * we need to know about the dependency of dependencies, even if we never use them directly. Information hiding is broken. * a single list will never do it. We intend to have many different applications that may depend on different versions of packages. Grok may need a newer zope.publication than your application does. A Grok extension may need an even newer version than Grok does. We'll be baking endless amounts of lists this way. If this information is inside the packages itself, the history will be automatically maintained with Subversion and existing releases. History therefore works: if I install Grok 0.11, I would get all dependencies of Grok 0.11 automatically without having to worry about external indexes. Information hiding works: if I use foo 1.3 and foo 1.3 knows it needs bar 1.7, it'll simply get that and I don't have to know about it. I don't even need to worry about the *existence* of bar. People have been saying that since Linux distributions use external indexes, we should too, as we are dealing with the same problem as Linux distributions. While the problem is similar, I think the nature of development makes our problems, and therefore our solutions, quite different from the way distributions do it. How are we different? We have many, many different small distributions (package + dependencies) that can be combined. We have such a small distribution for each application. We have such a small distribution for each extension. Not just that. We have such a small distribution for each *release* of an application. We have such a small distribution for each *release* of an extension. I therefore still believe that version dependency information should move out of external indexes and into packages. See also my earlier discussion of these problems and possible solutions: http://faassen.n--tree.net/blog/view/weblog/2007/09/26/0 Regards, Martijn ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
