Homebrew

10 June 2013

How to install, use, file bugs, create and contribute packages to Homebrew with some history of the project along the way.

Presented at TechMeetup Edinburgh in 2013 and TechMeetup Dundee, SydJS, ConFoo.ca in 2012.

Show transcript

0:00 Hello. Right, I'm going to start this talk with questions because I'm unconventional like that.
0:05 So, first question. How many people have either heard of Homebrew or have any idea what it is
0:10 and it's not about beer? Okay. How many people in here are running a Mac as their kind of
0:17 main-ish computer? Okay, about the same number of people. Okay, so if anyone gets really bored
0:24 or really confused with anything I'm saying, just shout and I'll try and go faster or slower or
0:29 whatever. How many people are using it? What was that? How many people are using it? Oh, in here.
0:33 Yeah. Sorry, I'm confused. What's going on? You didn't ask how many people are using it. I think
0:39 that's the most important thing. Oh, it's okay. I'm not a name like that.
0:42 It's just like me. Right, so that's where you contact me. Homebrew. Why? So, there was a man
0:53 called Max. This man called Max used a thing called Macports and got very angry with
0:59 this thing called Macports because it does things like this. So, if you want to install
1:05 Git on Macports, Git being a popular first control system, then what Macports has to do
1:10 is install all these things first. So, what I will come to in a minute is actually that is
1:16 somewhat unnecessary because if you install Git in Homebrew, to jump ahead for a moment, then
1:21 you have to install this. Oh wait, I have forgotten to fill out the slide. Or have I?
1:25 To explain something which you probably don't care about, but people like me do care lots
1:31 about. Basically, all this shit already comes with your computer. Well, almost a little bit.
1:37 So, if you have a Mac. So, that's the difference between Macs and package management Macs compared
1:41 to Linux or Windows or whatever. And then you have a whole lot of crap, particularly like open source
1:46 libraries and things like that, that are provided with your Mac. Now, Macports decides that actually,
1:52 they don't like the way Apple do things. So, they're going to go build all this stuff like
1:55 they're themselves, so they can kind of control their versions. But the disadvantage of doing
1:59 it that way compared to this way is that when you install Git with Macports, it takes a hell
2:05 of a lot longer to install. And generally, it uses all this crap that you probably don't care about,
2:09 you probably don't want, whatever. So, Macs went and decided, I'm going to make my own version.
2:15 And everyone said, "Aha, you're an idiot. No one will use your version and you'll have to do
2:20 all the Macports with it eventually." And seemingly, they were wrong. But anyway, so I ended up
2:25 meeting Macs and a few other people did as well. And Homebrew kind of began. So, Homebrew,
2:32 it's GitHub based and uses kind of Git. And GitHub is the kind of storage method and kind of back-end
2:39 way of transferring data around and all that fun stuff. And I kind of stumbled upon it because I was
2:45 having similar problems with Macports and got involved. So, nowadays, Homebrew has lots of users,
2:51 lots of hopefully mostly helping users. And like all the actual kind of work in the
2:55 repository is done by these seven people. So, Macs, who's the repository and anything,
3:01 in his name. And then there's kind of the rest of us sorted in roughly kind of commit order.
3:08 And basically, what happens is with Homebrew, unlike most other package managers, where if, say,
3:16 there is an update to some package, say there's an update to Git tomorrow. So, the way it works in most
3:21 package managers is you have like a guy who's a maintainer. And he notices and says, "Aha, there's a
3:25 been update to Git. I will go and then update Git, blah, blah, blah." But that relies, obviously,
3:30 on him having free time to do that, him noticing, him setting it up, whatever. And there's this very
3:35 much kind of this two-tier structure of the people who are kind of actually doing the stuff and then
3:41 the people who use it. Whereas with Homebrew, we have these people who actually are the only
3:46 people who have commit access to the GitHub repository. But then we have a few more people who've actually
3:51 made commits, and I've got their names on the next slide. So, I hope you can read that in terms
3:57 of the small one over the back. So, we've had 2,908 contributors to Homebrew as of today. So,
4:04 basically, the way it works with Homebrew is most people will go, which is one of the reasons why
4:10 we're the most, one of the top three kind of forked repositories in GitHub. So, people will fork the Homebrew
4:15 repository. They will add their own new package or an update to an existing package and then they can just
4:20 send us a pull request. I'll talk a bit more about the process of that later on. But basically,
4:24 it means that rather than us kind of seven people having to do a whole lot of work that you normally
4:29 get done with a package manager, instead, we are kind of almost more kind of wrangling and managing
4:34 other people's contributions, which is probably 95% of the work that kind of actually goes into Homebrew.
4:39 So, in case you think, oh, this Homebrew stuff sounds great. How do I get me some of that?
4:46 Very briefly how to install it. So, you need an Intel CPU, you need a Mac, which is running
4:50 10.5 or later, and then you need to install Xcode or this weird thing called command line tools for
4:55 Xcode, which basically is just Apple letting you have the compiler and stuff. But that will automatically
5:02 install as of Mavericks, so then things will be a bit happier. Do you have to do that with Macboards?
5:07 Yes, you do. You have to install it with Macboards as well. But if you want to install it,
5:14 we were one of the first cool people to do this thing, which makes security people very upset,
5:19 where you just say, "Let's just install stuff by piping a random script into our terminal and doing what
5:26 it said." We do prompt you and tell you what we're going to do and stuff like that. But anyway,
5:32 so that little one-liner will go and run the Homebrew installation script and install on your system.
5:38 So, once you have Homebrew installed, you might want to install something that doesn't come on Macs,
5:43 but it comes on Linux, like wget. So, if you type "brew install wget", then you will see something a bit
5:47 like this. So, it will download, it will run "configure", "make install", which if you're a kind of somewhat
5:53 Unix-y, open-source-y, Linux-y person, which will seem all terribly familiar. And then, at the end,
5:57 you have a bunch of stuff and the amount of time it takes to build it. And because we're really cool like
6:04 that, because on RSX it supports emoticons in the terminal now, we now have a little emoticon for beer.
6:11 And you would not believe how many people who otherwise seem to lead content normal lives got very upset
6:16 about that. So, what happens when you actually install it? So, what we do, again, slightly
6:24 different to other package managers, is we have a seller, and we separate each package into its own
6:29 prefix, and then we symlink everything into one place. I'll kind of walk you through that in a minute.
6:33 But basically, so when I install wget, rather than it stringing like shit all over your computer,
6:38 everything that wget actually has installed is under this one directory. So, I go to user local,
6:44 which is the default homebrew installation. If you don't like that, then leave. And then under the
6:49 seller, then I basically, I'm just saying list all the files under here, and then that's the stuff
6:54 that's installed. Basically, all of this is provided by wget itself. And then the only thing which is
6:59 actually homebrew files is this install receipt, which is basically just some kind of basic JSON
7:04 metadata. Again, different to other package managers, perhaps, we don't tend to kind of have like a big
7:09 package database and all these kind of binary archiving formats. Everything's on plain test from
7:13 disk, either in JSON or in Ruby files. So, if I want to install Qt, this is where we get a bit of
7:20 self-promotion. Because I got fed up of having things like that. You know, that is 46 seconds of
7:27 my life I'm never going to get back. And the problem is, well, sorry, the good thing is about Macs is that,
7:32 unlike Linux, where you can have all sorts of different distributions and different versions,
7:35 stuff like that, if I have a Mac and it's running the same off of the system, 10.8 or whatever,
7:41 then if you have a Mac that's running 10.8 as well, then literally all the libraries you have in your
7:45 system that we kind of rely on will be exactly the same. And equally, if I compile something on my
7:51 system, I can just copy that onto your machine and that works fine. So, basically, I created a kind
7:55 of binary packaging format, which are called bottles, obviously keeping in the theme. So, if you install Qt,
8:00 then this uses a bottle instead. So, it downloads the bottle from SourceForge until they shut this
8:05 down for using too much bandwidth. And then it just pours the bottle instead, which is a hell of a lot
8:11 quicker, just downloading and extracting a tarball than it is to go and do the same thing with building
8:18 a tool yourself. Particularly something like Qt, which takes kind of half an hour, an hour to build.
8:22 So then, much the same result. So, what I was saying with the Simlink stuff before,
8:30 basically, what we have is user local, which is our main kind of prefix, which we kind of install
8:35 everything into. And then, in the bin directory, if we look in here and we say, let's look at the
8:39 Simlinks. So, we have bin wget. It's not actually an executable, but it points instead into the seller.
8:45 So, basically, what we have is you only need to add user local bin to your path and then you can just go
8:51 and run and it will go and automatically Simlink everything into the right prefixes and yad yad yad.
8:57 So, the kind of cool thing about that is if you want to uninstall software, you can just remove the
9:00 prefix. You don't need to worry about, sorry, you can remove the place, the prefix it has in the seller.
9:05 And you don't need to worry about it kind of, as I said before, chucking shit all over your system.
9:10 So, to use homebrew, some kind of brief overview of stuff. So, you might run brew outdated. That basically says,
9:16 what do I have that needs upgraded on my machine? Then, surprisingly, you might type brew upgrade to
9:22 upgrade it. And then, if you want to upgrade the specific formula, like wget what you saw before,
9:28 then just brew upgrade. That's what you get. And some other stuff. So, we cache all your stuff in
9:35 to get that directory, the brew dash dash cache. You can list the contents doing that. And to view the
9:41 map page, which is unfortunately very infrequently updated and not in any way up to date with what the
9:48 code actually does. No, the map page works all right for anything you will need to do. It's frustrating for
9:53 people like me, who kind of use all the kind of nips and grindies, because then we're out talking.
9:56 If only you could find a technical right. Exactly.
9:58 A technical right it would work for free. But yes, so, as well as having lots of nice pull requests
10:07 from people, unfortunately, sometimes people have issues. And I'm not just talking about general
10:10 issues people have in life. We call them issues because that's what GitHub calls them and we use GitHub for
10:15 bug tracking. So, if you have an issue with homebrew, here are the things you should do before you bother me.
10:22 You should do these. Did we update? Did we run Brew Doctor? Again, although we kind of suck at
10:28 documentation, something we are quite good at is we have lots of cool little automated tools
10:31 like Brew Doctor. So, basically, pretty much whenever we see the same bug occurring again and again,
10:36 because some user has some stupid thing on the computer, we go and add a check for that in Brew Doctor.
10:41 And if you run Brew Doctor, then it will list a bunch of stuff that we kind of think is suspicious
10:46 or wrong or whatever in the computer. That does not mean your computer is having any problems, but it means when
10:50 you have problems, then we can kind of point out to you what they might be and try and suggest some sort
10:54 of fixes.
10:56 Are you running the latest version of Xcode? Have you completely ruined Macboards and things?
10:59 That's not just because we hate them. It's because they tend to interfere with each other and they pick up
11:04 each other's stuff and then it's all a big disaster. And you need to own user local by your own user.
11:12 Again, that's something we do. It's a little bit controversial. Again, it's a good to people
11:15 sometimes get upset. But the reasoning is on Macs, the applications directory is user writable as well.
11:22 So basically, if you can chuck applications in your application directory, why not be able to use
11:26 without changing to root and chuck applications in your user local.
11:29 So, again, how to debug stuff. Go and send our stuff, run brew install dash v, which is verbose,
11:41 for the thing you're trying to install, and then gist the output. If you haven't used gist,
11:45 it's basically like a paste bin service provided by GitHub, and do the same thing with brew doctor.
11:50 And all of this is on a troubleshooting page. Which, at the top of it, we have this.
11:55 Troubleshooting. Please, please, please, please, brew doctor before creating a ticket.
12:00 If you create a ticket, please paste your brew doctor. Now, you would be surprised how many
12:05 people do not paste their brew doctor output. And you'd be surprised how many people paste output,
12:09 which includes this at the bottom of it. And then say, "But I did everything you said!
12:16 Oh, you're such entitled jerks!" That's more my issues than that.
12:21 So, on to some slightly cooler stuff. Again, another thing that homebrew does,
12:26 which is one of the reasons I think it's got a bit more popular, is it's really easy to create new
12:30 packages. So, say we were living in a parallel universe where we didn't have wget in our repository.
12:37 So, you would say, "I want me a bit of wgets." So, if you find the URL for where the wget toggle
12:43 is on the internet, then you can type brew create, and then point it to the toggle,
12:47 and then it will download it, and then create a file for you. And then says, "Please run brew audit,"
12:52 which is another one of our tools for formula creation, which is what we call our package description.
12:58 So, this is probably going to be too small for anyone to read, but what we then generate in the right
13:03 place and stuff is this file here. And I'll just talk through very briefly what's going on here.
13:07 But basically, so this is our kind of formula description file. It's actually just a class
13:11 in Ruby. The subclass is from formula, and it's in a .rb file in the library formula directory.
13:16 And basically, we have gone and nicely pre-populated a lot of this stuff for you.
13:20 Pre-populated the name, the URL, the SHA-1. We don't have a version in that because we sniff it from the URL.
13:26 And then, you know, kind of some sensible stuff. And here, you have configure and make install,
13:31 and a test, which hopefully we're in. So, if I was to fix that up, then it would look something
13:35 like this afterwards. And you can see in here, basically, the stuff in orange, although that
13:40 should be orange as well, if you want to change that today. That's the only stuff that you've actually
13:44 had to enter manually yourself. So basically, for something like DoubleGet, the only thing you
13:48 actually need to enter is the home page and the test. So, as you can see, pretty easy to make new
13:54 deviant packages, compared to if anyone here has ever tried to make new kind of deviant packages
14:00 or RPMs. Again, they do things in a certain way, and that's okay. And they're a lot more perhaps
14:05 robust or thorough than we are, but it's a complete nightmare compared to stuff like this.
14:10 But anyway, then you can run BrutAuditWget, which basically goes and looks at this,
14:15 and makes sure you haven't made any silly mistakes or kind of bad practices or whatever. And then,
14:20 after that, you go and try and build this on your machine. And then,
14:23 if you pass this buildBottle, then that basically means that you can kind of distribute that binary,
14:27 remember the bottling stuff I talked about earlier, for a brewbottle, then you kind of generate a
14:31 binary. You can then stick that into your formula file as well. We obviously, like relatively sensible
14:37 people, don't accept random binaries from people because we don't want random binaries from random
14:41 people to be installed on all our users' machines. But if you're doing this yourself, or you can kind of
14:46 quite happily go and have your own formula, which you don't share with other people, then this type of stuff can
14:50 become quite useful. But yeah, so you've added your beautiful new package. You want to contribute
14:55 that to Homebrew. So first thing, if you don't already have it, you need to install Git. You need
15:00 to then update. And then you need to go on GitHub to our repository, which is github.com/mxcl/homebrew.
15:08 And then you need to fork it using this button here. Or I should have described that in text,
15:16 because their interface will change and therefore my presentation will be better.
15:20 But yeah, so then you get your own fork. For those who aren't familiar with, is everyone more or less
15:28 familiar with GitHub forking parlance and stuff? Stick your hand up if you're not.
15:33 Okay, cool. So very briefly, basically, that's just a complete copy of someone else's repository,
15:39 which you can make all your own modifications to. And then it means you can kind of submit them back
15:43 later on. Basically, so I have my own copy of the repository. This might seem slightly odd,
15:48 considering I have right access to the repository, but it's kind of useful sometimes for code review.
15:52 And obviously, if I want to kind of make random changes to Homebrew, I probably want to test them
15:56 myself before I push them to everyone. So here I've got a fork. I've made my own branch here,
16:03 called git-etc. And then what I'm going to do is make this pull request, which is what this is in here.
16:09 Um, sorry, by clicking that button there, which again, you know, you'll have to change next week.
16:14 So I then create this pull request, pops up a new that looks like this. Again,
16:19 something different last week, it looks different the week after.
16:22 But yeah, so basically it kind of has the vague contents of the commit, what I want people to look
16:26 at and stuff like that. And then that's the kind of commit at the bottom. And then what this will do
16:30 is get sent to the inboxes of everyone who does commit access on Homebrew and other random people
16:35 who follow the project. And we will see something like this, which is a nice, beautiful pull request.
16:39 This is how we do most of our kind of submissions, most of our kind of code view between the team.
16:44 And basically lets us kind of go through, view the code and kind of files change. And then we can review this.
16:49 So this is actually an outstanding pull request of mine, which, um, again, as you may have noticed,
16:56 because there were only seven of us, and probably only kind of four to five of us, like actively
17:00 working on Homebrew, it sometimes takes us a while to get to the pull request. So far we've had,
17:04 thinking that four years Homebrew has been around, we've had something like 25,000 pull requests.
17:11 And so we did take a while. I made this five months ago. Five months ago, Jack said, sorry,
17:17 keep meaning to look at it, we'll review soon. Not reviewed yet. But anyway, so if you are contributing
17:25 to Homebrew, to save you a bit of time, stuff we don't accept, we don't like self updating tools like
17:30 NPM. It's not that we don't like them. It's just, it doesn't play very nicely to install that with
17:35 Homebrew. And then it kind of updates itself. And Homebrew doesn't think it's the same version
17:39 as it is, and all this type of stuff. And niche stuff as well. Again, you would think this would
17:44 be common sense. But if you wrote a project over the weekend, and it's a 0.0000001 release,
17:50 and no one has ever used it, and everyone you've ever shown it to think it's rubbish,
17:53 don't submit it to Homebrew immediately, because chances are, politely, we don't care, and other
18:00 people don't care yet. We may care, and other people may care later, but we don't yet. So save
18:05 yourself some time and hold off for a little bit. But anyway, so all this stuff, all this effort,
18:10 as you've seen before, there were kind of seven of us. It's kind of tricky to get all this stuff done,
18:14 particularly with binary packages. So with binary packages before, anything you'd install Homebrew,
18:19 which is kind of using a binary package using a bottle, was previously done by me going and having
18:25 multiple VMs with each version of OSX on my machine. And I would go and have to go manually build the
18:31 package on each VM, and then upload it. So this became a little bit unsustainable, particularly when
18:37 I was on holiday and things like that. So we decided we would do a Kickstarter. And basically,
18:43 what we told people to Kickstarter is, I wrote a little tool while I was away and kind of had some
18:47 time off work last year in Sydney. And wrote basically a little tool for kind of beginnings
18:53 of a sort of CI system called brew test port. Again, another little automated thing. Basically,
18:57 just trying to turn our review process into code. So what this does is I'm getting it to test a
19:03 particular pull request. It will then download the pull request, make sure there's nothing wrong with
19:08 the system, make sure there's nothing wrong with the changes in the pull request, which in this case,
19:11 was this package, "MOM", it didn't change. Download it, install it, bottle it, make sure that's okay,
19:17 uninstall it, and then return the state. So I wrote this little tool. And we basically went and asked some
19:23 people for some money. So we asked people for £1,500, so we could buy a Mac mini. And thankfully,
19:31 we got quite a bit more than that. We got £15,000. In fact, we got our £1,500 two hours after the
19:36 Kickstarter began, from 755 very nice people. Again, if you're interested in such things, the graph of
19:44 money looks like this. So that was, the green line is our £1,500. And I believe, so that was basically just
19:53 everyone going mad. And then somewhere around here, it was John Gruber, who reached Daring and Firewall,
19:58 retweeted us, and a bunch of other people. And we were also lucky enough to be featured on the
20:03 Kickstarter homepage for a couple of days and all that type of thing. So yeah, so we got lots of money,
20:07 and it's great. If you're vaguely interested, if you're the type of person who's ever doing a Kickstarter,
20:13 so our breakdown looked like this. We got lots and lots of people off of Twitter. 22% of people clicked
20:20 directly from Twitter and gave our money that way. And obviously, that excludes people where there's
20:25 no referral permission, which is about quarter. We put it on our GitHub page. We got a bunch of
20:30 referrals from that. Some people found us through search. And then obviously, we got 500 quid, which
20:36 is pretty nice from being on, well, sorry, 600 quid from being on the homepage, and 500 quid from being
20:41 like a featured project in the kind of open software section. So instead of one Mac Mini, we got four
20:47 Mac Mini's. Hooray! So basically, we were able to get all these. It was pretty awesome. We had to set
20:54 up like an organization in the UK, so Homebrew actually kind of exists, because I didn't want HMRC to
21:00 say, "Aha, you need a peer to have 15,000 pounds." And because we initially didn't have a server farm,
21:07 my office had a thing that looked a bit like this. And my wife was continuing asking, "When are these computers
21:14 going to go away, are they sitting here forever?" And I just made sure I kept the electricity bills from
21:20 them. But we had nice, very nicely, a company called Positive Internet, who I kind of randomly
21:25 interacted with their CEO on from a kind of podcast stuff he was doing. They offered to us in their
21:32 data center called Positive Park, which is down near Cambridge. So I got on the train with all the
21:38 computers, which is quite a scary thing to take like 8,000 pounds worth of computers on a train.
21:44 And then we got a lot of nice stuff, a lot of switch, and time capsules to back everything up.
21:50 And then we still got nice stuff for that. And then here we go, and there's cables everywhere,
21:56 so it's probably getting on fire. But yeah, so it's pretty awesome. And now what we have is we have a
22:01 Jenkins instance, which goes and runs pretty much all the time. It basically, so we have kind of
22:07 several things it's doing. So basically everything, every change that's made for Homebrew, it goes and
22:11 runs to make sure that it kind of passes all our little tests, and then emails. If it doesn't,
22:17 it checks all pull requests. And GitHub has a neat pull request integration now, so you can actually
22:22 basically mark in big red letters, this pull request succeeded or failed or whatever. So that's kind of
22:27 nice. And we've found since doing that, that kind of automated process, a lot of users will go and
22:31 kind of start fixing the issues themselves without us having to go and tell them, which is great,
22:36 because as I said, probably 95% of our workload before was telling people exactly what the output of
22:42 these tools are. We would just download them onto our local machines. The tool would say, "This is bad." And then
22:47 we would type in, "This is bad." And then, you know, so this has made things much better. And then it's also
22:52 mean that it's much, much easier for us to build binary packages now. I just basically kick off the job,
22:57 and then in a couple of minutes, it's built the binary packages for all the operating systems.
23:01 So across those kind of multiple Mac minis, we basically have it running. We have one that's
23:07 just doing server-y stuff, and then the kind of current and past two generations of OS X.
23:12 So that basically lets us build all our binaries and test stuff pretty thoroughly between them as well,
23:18 which is quite nice. And we have a mailing list, if you're particularly, I don't know, board or something,
23:24 then you could subscribe to the mailing list of "Only Build Failures in Home Group."
23:28 It's a fun reading on a Saturday afternoon. So yeah, so if anyone is kind of involved with,
23:35 like, an open source project or whatever, and you kind of feel, "Oh, man, it really,
23:39 we had some hardware." I would really consider, I really advise you, sorry, to consider something like
23:44 Kickstarter because it seems to have this weird traction in that people, because it's time limited,
23:51 or basically the way it works, if anyone is not familiar, is you need to say an amount of money
23:55 you want, and you get a month or however long you choose to raise that amount of money. If you raise
23:59 that amount of money or more, you get to keep it. If you don't get to raise that amount of money,
24:03 you don't get to keep anything. So it seems to kind of get people engaged, and lots of people are
24:07 kind of more willing, similarly, to hand over stuff in exchange, you know, ridiculous stuff like,
24:12 you know, 250 quid, and you get a t-shirt and a pun class, and people are more than happy to kind of
24:17 hand over that money. Although it does mean that you need to get t-shirts printed and stuff,
24:23 which is significantly harder than any part of writing the code on.
24:25 Yeah, so I guess that's basically the overview of Humbley, so if anyone has any questions,
24:32 feel free. Just on that Kickstarter bit, did you have to pay any tax in the end for when creating
24:41 that corporation? So it's created as basically a non-profit, just like committee, sorry, community
24:49 organization, so you don't need to pay any tax because it's in no way related to me, it's just this kind of
24:54 floating organization. What Kickstarter takes, between Kickstarter and Amazon
24:59 marketplace, they take about 10% of the money raised, but then again, it's such a good kind of
25:04 crowdfunding tool that you don't really mind that.
25:06 You said several slides ago about the, one of the things you ask people is that it's not working,
25:15 have you got the latest version Xcode working? Yeah.
25:17 So I've got lots of old Macs, and the answer to that is no, because I can't put them on there,
25:23 because they're so old, but they still work. Is there any way you would get this stuff to work
25:27 without using Xcode as the developer? So we basically, in that case I was being overly concise,
25:36 so it's basically the latest version of Xcode for whatever operating system you are on. So for the older
25:42 versions that don't get kept up to date with Xcode, then it's kind of fun. The short answer is yes, but only for kind of new versions. So we've been kind of petitioning Apple
25:52 to try and get, because obviously people don't want to install like a, what was at one stage
25:57 like an eight gig package, just to have a compiler on their machine.
26:00 We have got some incremental progress with the kind of command line tool stuff, which was like a separate
26:06 couple of hundred mega installer. And then in the latest version, we've kind of been talking with
26:11 the two guys there, and it's kind of more or less perfect in there. And if any of you have kind of used
26:17 the latest versions of OSX, you'll see if you try and do something with X11 or Java, then they're not
26:23 installed by default. And if you try and do something with Java, it will just pop a little box saying,
26:27 if you're trying to use Java, would you like to install Java? So it's now starting to do that with the compilers
26:32 as of 10.9, which obviously hasn't been released yet, but is in betas. So our lives will become a bit
26:38 easier then, but we're still going to have to support new versions for ages. So sadly, in terms of
26:44 distributing our own compilers and stuff like that, it's not actually that easy because
26:49 on Macs particularly, there's a lot of, so there's a lot of stuff that's open source, probably 75% of it,
26:55 but then a bunch of it is like Apple's private headers and all this type of stuff, which we can't
26:59 redistribute. I mean, someone could and other people do, but we don't want the legal pin.
27:04 How do you manage versions? We don't, basically. Well, basically what we do is in Homebrew, we have
27:16 like only the latest version of each thing effectively. And then we have two sort of
27:22 alternate strategies that are kind of hacks around the fact that we don't really manage versions.
27:26 One is you can always just go through the git history and we have a command that does that
27:30 and just pull out an old version and install it that way.
27:33 Would that be in parallel?
27:35 Oh yeah. The versions quite happily exist. I guess that's the difference compared to other things.
27:39 Because of our kind of seller system, you can have as many packages as you want with as many
27:45 versions as you want all in parallel. And even if they kind of conflict in terms
27:49 of naming and all this type of stuff, then they're just kind of nicely segmented away.
27:53 The other kind of slight hack we have is we have like a Homebrew versions, like other repository,
27:58 which contains, you know, like MySQL with a version number appended to the name.
28:03 And then, you know, that's just a kind of static version that kind of stays along.
28:07 Well, that's great. Thank you very much, everyone.

Mike McQuaid

Homebrew