If Apache is configured to browse a Subversion repository, its files and directories are shown as of the latest version by default, for example:

http://svn.apache.org/repos/asf/subversion/trunk/

If you want to browse the content of older revisions, there is a non-trivial way by inserting /!svn/bc/REVNO between the base URL of the repository and the path component of the target directory inside the repository, for example you can browse the contents as of revision 1234123 like this:

http://svn.apache.org/repos/asf/!svn/bc/1234123/subversion/trunk/

Gource is a really cool open-source software to visualize the revision history of your projects, whether you’re using Git, Bazaar, Mercurial or Subversion.

https://code.google.com/p/gource/

The project website has many cool example screenshots generated from the repositories of famous projects such as the Linux kernel or Git.

Here’s what some of my projects look like in gource:

1. Revision history of Bash One-Liners:

2. Revision history of the RecipeNotes App:

To generate these videos I used the following commands on Mac OS X:

gource --file-idle-time 0 --seconds-per-day .3 -640x480 -o gource.ppm
ffmpeg -y -r 60 -f image2pipe -vcodec ppm -i gource.ppm -vcodec libvpx -b 10000K gource.webm

To clone a remote Subversion repository using Git through a proxy server, edit the ~/.subversion/servers file appropriately:

[global]
# http-proxy-exceptions = *.exception.com, www.internal-site.org
# http-proxy-host = defaultproxy.whatever.com
# http-proxy-port = 7000
# http-proxy-username = defaultusername
# http-proxy-password = defaultpassword

Note that even in Windows, the correct path is actually ~/.subversion/servers when using git-svn, even though this is NOT the normal configuration directory for the native svn.exe. For example in Windows 7 svn.exe typically uses the path C:\Users\YOURUSER\AppData\Roaming\Subversion.

This was quite confusing to me at first, because after I got svn checkout working well by editing C:\Users\YOURUSER\AppData\Roaming\Subversion\servers I was surprised to find that git clone svn still had the proxy issue.

In case you were wondering, the http_proxy and https_proxy environment variables are ignored by both Git and Subversion.

On Mac OS X, for some reason the default device for displaying plots is Quartz. This can be inconvenient, since for example the savePlot function works only with X11 devices with Cairo support.

To change the default device, I created ~/.Rprofile like this:

setHook(packageEvent("grDevices", "onLoad"),
    function(...) grDevices::X11.options(type='cairo'))
options(device='x11')

The setHook creates a hook so that when the grDevices module is loaded, it sets the default type of X11 devices to cairo.

The second line sets the default device to X11.

Both of these lines are necessary, otherwise the default device would either not be X11, or it would not be the correct X11 type.

I had this strange issue the other day. My account password has recently changed, and for each Subversion repository linked to that account I had to re-enter my password. Normally it is enough to re-enter once per repository: Subversion updates the corresponding authentication setting file so that I don’t need to enter it again. But for some repositories it kept asking for it…

After some digging around, I realized that my user did not have write access to the file that sores the password. That is easy to fix once you know what to look for, and if you know which file it is. However that can be tricky if like me you don’t know how Subversion organizes its settings files…

In Windows 7 (using the Git shell) you can find your Subversion setting files that you don’t have write access to like this:

find /c/Users/YOURUSER/AppData/Roaming/Subversion ! -perm -200 -type f

This can be useful to confirm your suspicion about filesystem permission issues. If you don’t care about all that, you can just add write permission to yourself on all files indiscriminately with:

chmod -R u+w /c/Users/YOURUSER/AppData/Roaming/Subversion

How did it happen that my write permission has disappeared on some of the files? I haven’t the foggiest idea…

Step 1: run this in a terminal:

defaults write com.apple.Finder AppleShowAllFiles YES

Step 2: restart Finder: hold down the alt key, right click on Finder’s icon and select Relaunch.