Implementing single script build - non-portable dependencies

Question

It seems that a build system best-practice is to have a single script that can build all source and package the releases. See Joel Test #2

How do you account for non-portable dependencies? For example, if you code for .net 4, then you need .net 4 installed on the box. Standard MS release .net 4 is not xcopy deployable (unless I'm mistaken?). I can see a few avenues:

1. the dependencies are clearly stated in some resource file (wiki, txt, whatever). When you call the build script, the build will fail if you don't have the dependency installed. This is an acceptable outcome.
2. The build script is responsible for setting up the environment. So if you require .net 4 and its not on the box then it installs it for you.
3. A flavor of #2 - instead of installing dependencies, the script spawns a pre-packaged image (virtual machine, Amazon EC2 AMI) that is setup with all dependencies
4. ???

Answer 1

For implementing a build script you have to ask yourself, how much work you want/can spent on it. This leads to the question how often you have to set up the build environment. I can see #2 would be the perfect solution, but i would need a lot of work, since usually you have more than one non portable dependency.

So we use #1 one. And it works quite well. The most important thing is, that the build script is starting with some sort of self-test. It looks for everything which is needed to build the whole software and gives an error if something is not found. And it gives a clear error message, so that any new guy knows what to do to make it running. Of course as with a lot of software it is nearly never finished and gets extended by needs. The drawback that this test can take some seconds is insignificant when whole build process needs more than minutes.

A wiki (or even sth. else) with the setup solution was not a good solution for us, since after three month nobody knows where this was, but the build script is used every day.

The build script itself is a set of a lot of different things, which where chosen by needs. It is starting with a batch (we are using Windows) which invokes a lot of other things. Other batches, MSBuild, home grown tools. Each step by it self is checking for its own dependencies, to have the problem local and you can see three lines later why this special thing is needed.

Answer 2

Number 2 states "Can you make a build in one step?" As described this means for a development team to be effective the build process must be as simple as possible to reduce errors in the build process and insure consistency. This is especially important as a team gets larger. You want to make sure everyone is building the same thing. (What is done with that package should also be simple, but it is not as important IMHO.) Msbuild is great at this; they provide the facilities to set up a build server that access the source control system independently so the developers actions can't corrupt the build environment. I highly recommend setting up a build server using TFS -- many build issues will go away and you will have the 1-click build Joel describes.

As for your points about what that package does for deployment -- you have many options with MS, but the more "one click" you can make it the better. I believe this is slightly different than Joel's #2. In his example he describes changing what software he will use for the install not because one performs with fewer steps, but instead because one can be incorporated into a one step build.