Over the last few days I've been blogging and tweeting about using NuGet without committing the packages folder to source control. David Ebbo blogged about using a pre-build event to fetch packages at build time.

Unfortunately, this doesn't work on AppHarbor because build events are not supported. If you try, you'll find the pre-build step doesn't fire and the build fails due to the missing dependencies :(

I voted on (and tweeted about, lots) a feature request about supporting NuGet natively on AppHarbor. The request has had quite a few votes, and Friism said they'll probably implement it, but in the meantime, this meant I couldn't deploy to AppHarbor. I didn't want to add my packages folder to source control, because even once I remove it when AppHarbor supports NuGet natively, it'll still be in the history (and therefore every clone), which I'd like to avoid.

I scratched my head a little, and re-read the proposed spec for baking this functionality into NuGet/MSBuild (to be honest, I don't actually understand what there is to improve!). The mentions of MSBuild got me thinking - custom build targets!

I opened up my csproj file in Notepad, and scanned through for the "BeforeBuild" step that's included by default but commented out. I removed the comment, and moved my pre-build event into the target:

<Target Name="BeforeBuild">
	<Exec Command="&quot;$(SolutionDir)Tools\NuGet&quot; install &quot;$(ProjectDir)packages.config&quot; -o &quot;$(SolutionDir)packages&quot;" />

First I checked whether this worked locally, by deleting my packages folder and running MSBuild from the command line. Success! I added in MarkdownHelper and added some test code to a view:

@Html.Markdown("We can use **Markdown!**")

Everything worked fine locally. An "hg ci" and "hg push" later, Bitbucket notified AppHarbor, AppHarbor checked out, built, and successfully deployed!

So, it turned out to be quite simple to get it working. I've also notified David Ebbo to see if he'd update his post with this info for anyone reading there that's using AppHarbor! :-)