Source Control for your Operating System

I think that I’ve realised why I feel so uncomfortable using MacOS X and Windows for “Real Work”. They’re fine for playing MP3s or browsing the web, but when it comes to developing software I get scared.

For me, developing my own software usually involves installing other software and upgrading existing software on my computer and when you don’t have a package manager that’s really hard to do reliably and reproducably. I’ve tried doing this by hand, keeping track of what versions of what I installed where with what build flags, trying to write scripts that can reproduce my build environment and trying to keep track of which dependencies are build-time and which are run-time. I’m bad at that, but that’s the kind of thing that computers are really good at.

Now, I know that Cygwin and MacPorts each have their own pseudo-package system, but that only covers the UNIX libraries and utilities that are ported, not native tools, and they don’t integrate with the tools you use when producing packages to ship. When you’re developing a Mac or Windows application how do you keep track of which libraries need to be included in your installer or disk image? There must be a trick, but I’ve never come across a tool for the job. The Debian packaging tools do an amazing job of analyzing the dependencies in software that has been built and mapping them to package dependencies. There are even tools for creating VMs that you can use to test that the autodetected dependencies are correct. All automatic, reproducable, testable.

So today, out of the blue, I found a metaphor that I’m satisfied with to explain to my Windows and Mac developer friends the way I feel about developing on their platforms. It’s like programming without source control. Developing on Linux and with source control I feel safe - if anything I do has unintended (or worse, unnoticed) side-effects I know that I can get things back to where they were before, or at least work out what happened. On Mac and Windows I’m back to when I was writing Pascal programs in DOS where I’d type a few lines, save and never be able to make my program work again.

Aside 1: At least with Windows I can do everything in VMWare which gives me snapshots and roll-back, Apple’s DRM prevents me doing the same for MacOS. Fail.

Aside 2: I feel almost the same about Ruby gems. It’s a package system but a terrible one. It’s like being forced to use RCS when I’ve got git sitting right here. I do understand why Mac Ruby developers seem to think it’s the best thing since sliced bread - I remember in 1995 when I was first introduced to RCS.