As MacPorts is rather unhappy with Xcode 4.3 (understandably, with all those changed paths), I invested a fair amount of effort to get it recompile rTorrent (which I’d been running in a screen-session on my Mac mini). I got it work (xcode-select + setting the Developer-folder in /opt/local/etc/macports.conf to either “/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain” or “/”), but while searching around, I also came across Transmission‘s headless daemon and web-interface.

So, here’s how I built and configured the headless daemon on OS X (with Xcode 4.3):

1. Get the source-package, e.g. transmission-2.50.tar.bz2
2. Copy the source of libevent2 into “third-party/libevent” (“mv ../libevent-2.0.17-stable third-party/libevent” inside the Transmission-directory).
3. Build via “xcodebuild -project Transmission.xcodeproj -target transmission-daemon -configuration Release”.
4. Run the daemon so it creates its initial config in “~/Library/Application Support/transmission-daemon”.
5. Edit the configuration in settings.json (whitelist, watchdir, ports, speeds, …).
6. If you want to use the web-interface, copy its files: “cp -R web ~/Library/Application Support/transmission-daemon/”
7. Re-start the daemon.

This worked well for me and I’m quite impressed with both the web-interface and Transmission itself.