For the Mac users out there, here are some instructions for fetching the latest Flex SDK source code (aka “trunk”). Note that I’m saying LATEST. It might not be stable. Heck, it might not even build.

For a GUI client, I use SmartSVN because it was the first one I stumbled over which:
- Has a free, functional version.
- I figured out how to use quickly.

If you can recommend another, please point me to it. I’ll be happy to give it a try and post instructions.

Of course, the instructions are basically the same on any OS. But it’s always nice to see very specific instructions for the OS one is using.

Instructions using the svn command line client:
1. Get it (http://downloads.open.collab.net/binaries.html) and install it.
2. Run this command:

svn checkout http://opensource.adobe.com/svn/opensource/flex/sdk/trunklocal-directory


Instructions using SmartSVN (6.0.2):
1. Get it (http://www.syntevo.com/smartsvn/index.html), install it, and start it.
2. Project > Check Out.
3. Choose Quick Checkout and fill in:
URL: http://opensource.adobe.com/svn/opensource/flex/sdk/trunk
Local Directory: whatever works for you
4. Click Continue, then Finish.

Building the SDK:
Assuming you have recent releases of Ant (I have 1.7.0) and Java (I have 1.5.0_16-133):
1. Bring up a terminal window.
2. cd to the trunk directory that you fetched above.
3. Run: ant clean main

Note: I don’t have FLEX_HOME, JAVA_HOME, or ANT_HOME defined anywhere, but there is some documentation which claims these are needed. Do what works for you.

References:
Getting source code:http://opensource.adobe.com/wiki/display/flexsdk/Get+Source+Code
Building the SDK:http://opensource.adobe.com/wiki/display/flexsdk/Build+and+Test