
The Mac turns 28 today. It has come a long way, and it’s amazing to think about how the original Macintosh compares to, say, a 27-inch LED-backlit aluminum-and-glass-clad LCD iMac of today. I think one could imagine the iMac being a successor to the original iMac, from its exterior design, through the software it runs, to the input devices used to interface with it.
But, will the Mac make it to thirty — and still be recognizable as a Macintosh? A lot can change in the next two years.
I’m updating the settings for my Harmony 520 and discovered that I couldn’t change the names of activities in Harmony Remote Software v7.7.0. I am not alone, but I couldn’t find a solution. While I had the problem on Mac OS X 10.6.8, others reported problems on various other operating systems, including Microsoft Windows.
The software wouldn’t let me to change the name of more than one activity. Instead, it would let me select and highlight the text, but not edit it. It was maddening, especially when it would beep instead of accepting characters I typed.
Then, by happenstance, I clicked over to Safari to do something while I was frustrated. When I flipped back to the Harmony Remote Software, it finally accepted my typed changes.
Therefore, if you have come across this problem, try switching to another application and back to the Harmony software again.
I’m continually astounded at how aggravating the Harmony remote can be, after all the hype. I suppose it is still better than many, if not most, of the alternatives, but that isn’t saying much.
I’ve now spent just over one year with my EVIL (electronic viewfinder, interchangeable lens) DSLR-like camera, the Sony Alpha SLT-A55V. It has been a rewarding year for me photographically.
I can’t express how much more fun it is to use this camera compared to anything I’ve had earlier. I was in the land of point-and-shoots (including a “super zoom” of its time, the Olympus C-750UZ) before the SLT-A55.
There isn’t much I don’t like, and most of that is simply comes with the territory of a DSLR-like camera. The extra expense and bulk and even uncertainty (which lens should I take?) of having interchangeable lenses could be a drawback. All things considered, I am a happy and satisfied SLT-A55 owner, nothing more.
But beyond that, I have found this camera very freeing. I worry less and less about the pictures I take. I love the camera’s:
There’s certainly more, but this camera has removed so many barriers for me. I’ve taken at least 17,375 photos with it in a year, and I haven’t counted how many video clips. The best part is that I think a higher percentage of my images have been good than ever before.
The camera has gotten some press but I’m continually surprised that I don’t see it advertised more or presented in the weekly sales circulars (where it’s all Canon and Nikon, predictably).
I had a repeat of a problem that I’ve probably had many times over the years. I wanted to write down the solution before I forgot it, because it had been long enough since the last time that I’d forgotten the fix.
Let’s set the stage: I wanted to SSH into a remote system. In my case, that remote system was a Mac OS Snow Leopard system. The client was also Mac OS X.
On that remote system, I had enabled sshd. This is done on Snow Leopard with System Preferences > Sharing > Remote Login. (In the Sharing System Preferences, you set up the users that are allowed to remote log in, either allowing all users or setting up an ACL that only allows specific users. If you set up the ACL, it should supercede whatever additional user/group login restrictions you’ve configured in /private/etc/sshd_config.)
Then, I tried to SSH from my client system. Instead of a successful login, I was told the following — before I was prompted for a password.
Scratching your head, you add verbosity to the SSH connection attempt.
I searched for other people having the same problem with “debug1: SSH2_MSG_KEXINIT sent,” because other people always have the same problem and some of them wrote about it and some of those solved it. Right?
Well, in this case, the other solutions I found were not helpful to my specific situation. But many people responding to pleas for help did mention the always-good advice to “check the server logs.” Which I could do, so I did.
In the secure.log, I found several groups of lines like this corresponding to the times I had tried to log in:
That reminded me of the common problem with SSH host keys on Radmind-managed computers. See, Mac OS X will try to create the host keys if they are missing, but not if they are zero-length. On Radmind-managed computers, it was trivially easy to get zero-length SSH host key files in /private/etc because the tendency was to manage them with negative transcripts. Files listed in negative transcripts would be created if they were missing, but they would be created as empty files (by design).
Empty SSH host key files will prevent you from logging into that system with SSH.
I checked the server and — sure enough — the host key files were zero length. I deleted them, then stopped and restarted Remote Login for good measure. This solved the problem, and I could log in from the client.
I was trying to install Dulwich on a Mac OS X Lion system this week and ran into difficulty. I kept getting installation failures that included a missing “python.h” and, eventually, llvm-gcc-4.2 failed to compile the module.
I found the situation frustrating, partly because I pretty much own the top search hits about how to install Dulwich and Hg-Git on Mac OS X Lion, thanks to some earlier article.
It turns out that I had reinstalled Lion about two weeks ago, and had not reinstalled Xcode 4. So, I updated to Xcode 4.2 and this completely eliminated my problem. Presumably, it would also work for you — and for future me, since I’m likely to repeat this — even if Lion hadn’t been reinstalled in between.
Things that didn’t work included but were not limited to:
I had a need to read some settings from a Python script on Mac OS X recently. I wanted to be able to change selected parameters for the script — some of which could be site or implementation specific — without embedding them directly in the code. Since the script was Mac OS X-only, using a property list seemed like a good idea.
With customizable settings from a property list, a script could become useful and more customizable for a wider community — or even different internal audiences.
I thought reading preferences was going to take a lot of effort. I was, however, pleasantly surprised at how easily I was able to accomplish it.
Asking others who had been down this route before resulted in some links to Apple docs. I wanted a more concrete example of how it was done in Python, and I got a great one.
That example came from reading the source to munkilib from the open source project, Munki. Since Munki had its own preference file, it needed to read from it, and its example was very enlightening.
Frogor directed me to a specific spot in the Munki code. That spot demonstrated how to read a preferences file with CoreFoundation.
Munki also has its own internal defaults for preferences. The munkilib/munkicommon.py example showed how to implement default settings in their absence in a property list. That provides a fallback position so that you always have some value available. In Munki, setting the defaults was done within a function. It seemed that it would be more generic if those defaults were separated out of the preference-reading function.
My own example of how to read a plist is outlined below. This focuses on just what you need in order to read the preferences and provide default settings for a larger script. A single set of preferences can be shared between scripts, and each script can encode its set own defaults. While you can create your own keys and values, for the example below, I will use the keys “StringPreference,” “BooleanPreference,” “ArrayPreference,” and “DictionaryPreference.”
The script won’t do anything yet, until we create a main() or other functions to call the get_preferences function. Since you’d be reading preferences as part of a larger script, this is fine for now. However, with what’s written already, you can test out reading preferences interactively with the shell and Python interpreter.
That’s it, the expected results were returned. Notice that the output for StringPreference and BooleanPreference are taken from the property list, while the empty array and dictionary come from the default_preferences in the script.
Update: Greg pointed out that there is a certain degree of danger using #!/usr/bin/env python as the shebang line in the script. Should a system have a non-Apple installation of Python, then /usr/bin/env python might return that. Another Python is probably less likely to be able to bridge CoreFoundation, and thus wouldn’t be able to use the CFPreferencesCopyAppValue call to read preferences.
I think the overall shebang danger is small because few Mac OS X systems will have an alternative Python installed, but clearly your chances of that increase in certain situations. To eliminate this risk, do what Munki does and insert the #!/usr/bin/python shebang instead.
The news broke tonight that Steve Jobs died. That’s still sinking in — but as I paused for reflection, I was immediately taken back to an exciting moment when I was much younger and merely a few feet away from him.

That was at Macworld Expo 1998 in New York, after his keynote address. I didn’t talk to him, but it certainly made my mental highlight reel.
Searching for that photo, it struck me that I’d been about the same distance away eight years later. The pictures weren’t as good and there was far more of a crowd, but you can see Steve in them.

Goodbye and Godspeed, Steve.
In previous articles, I described how to Install Mercurial 1.9, Dulwich, and Hg-Git on Mac OS X Snow Leopard and Install Mercurial 1.9, Dulwich, and Hg-Git on Mac OS X Lion. For either of those operating systems, we can further extend Mercurial with support for connecting to Subversion repositories. While we could enable the bundled Convert extension, the Hgsubversion extension adds live access to remote networked Subversion repos, so it sounds more interesting.
My personal goal in doing this is to be able to work with the InstaDMG repository. It is hosted on Google Code, uses a Subversion repo, and depends upon Subversion keyword substitution. It presents an interesting challenge.
So, let’s install Hgsubversion to add Subversion support to the Git support we’ve previously set up. We need to take the following additional steps, going beyond what is done in the previous articles. To continue, you must already have installed:
Hgsubversion also needs Subversion to be installed. The Mercurial extension then has two different ways of working with Subversion. The Hgsubversion docs I read indicated that Subvertpy is preferred over the other method — using Subversion’s SWIG bindings — so we’ll install this additional Python module first. The docs also recommend running tests on Hgsubversion before using it on projects, so we will try that, as well.
Start with installing Subvertpy:
easy_install command in Terminal.easy_install again to get hgsubversion. However, version 1.2.1 in PyPi didn’t work for me. So, to get a more current working version, I went to the source repository to get the latest software.That’s it! Hgsubversion has been installed and enabled. Even though we got errors from the tests, we can proceed.
kwdemo. You must be in the directory for the cloned repository and have enabled the Keyword extension.Notice that “Revision: 425” is returned when keywords are expanded, replacing the “$Revision” keyword. This is precisely what we need with InstaDMG, where the revision information is reported when the instadmg.bash script is run.
Hg-Git is the Mercurial extension to use if you want to connect to local or remote Git repositories. I exclusively use Mercurial and Hg-Git for all of my Github transactions, so I can personally vouch that it works.
Now that Hg-Git has been updated to better support Mercurial 1.9, let’s see if we can get an Hg toolchain working on Lion. Since I did that on Snow Leopard a few days ago, Hg-Git has made it into PyPI. The installation instructions this time are a bit more streamlined, because we can now use easy_install to get Hg-Git and its dependencies.
To get the toolchain set up, we’ll need Xcode. The Xcode suite includes tools we’ll need to make Python easy_install work, along with Subversion (a prerequisite for Hgsubversion, which I’ll talk about in a later article) and other useful tools.
The Xcode installation is a multi-step install process. Both current download methods — the developer download through connect.apple.com (if you have a paid Mac Developer Account) and the Mac App Store — give you an “Install Xcode” application. That application runs a second, real installer that you have to finish before you actually have the Xcode tools available in a ready-to-use state. This is very similar to the situation for Mac OS X Lion, so you may be developing a sense of familiarity with the situation.
To install Mercurial:
To add Hg-Git to Mercurial on Lion:
That’s it! Once Mercurial 1.9 plus Hg-Git 0.3.1 or later are installed and you’ve enabled Hg-Git in your ~/.hgrc, you are ready to use Mercurial with local and remote Git repositories.
Here is my current installation method for Mercurial 1.9 and Hg-Git on Mac OS X Snow Leopard. I use Hg-Git on a sporadic basis to work with projects on Github. That activity is frequent enough that it’s really helpful to be able to get Hg-Git set up and working quickly.
I had a rough time with Hg-Git after I upgraded to Mercurial 1.9 a few weeks ago. It was notable because that was the first time I can remember having incompatibilities between this stack of software. Since then, Hg-Git has changes available that allow it to install and work with newer versions of Mercurial, including version 1.9, and the most recent Dulwich release. These changes weren’t as readily available at the time I upgraded, so I thought it was worth writing this to remind me how to put the right pieces together.
I don’t yet have a working installation method for all of this software on Mac OS X Lion. I ran into a stumbling block getting Dulwich installed there, and Dulwich is a necessity for Hg-Git. Update: The situation changed a few days later, and I have instructions for Mac OS X Lion available now.
This may have been a problem isolated to the particular Lion system I was using. I haven’t had the chance to duplicate it elsewhere or troubleshoot the problem on the system where I encountered it.
Update: Since I wrote this, Hg-Git 0.3.1 became available through PyPI, which means you can install it via easy_install. You no longer need to clone the Hg-Git repository and run the setup process manually. Instead, you can run the following single command to get Hg-Git 0.3.1 and its dependencies (Dulwich 0.8.0 or later):
This simplifies the instructions quite a bit, but I leave the original steps above for reference.