When "Copy Local" doesn't copy locally

There are days when software development is fun, challenging, rewarding. Then there are days like today when frustration makes me want to hurl my monitors against the wall and generally destroy my office like Keith Moon.

The day started innocently enough as I tried to wrap up some final release details by executing my stable old deployment scripts. By 'stable' and 'old' I mean they haven't had to change in over a year and have staged several successful releases. One of the scripts reported that it couldn't find Oracle.DataAccess.dll. That's odd, I thought, and proceeded to waste 2 hours investigating why my reference wasn't copying locally. Because the scripts had been so seemingly reliable for so long, I had forgotten their flow. I couldn't remember who was responsible for copying Oracle.DataAccess.dll to the proper deployment location so I had to take a trip down memory lane and get reacquainted.

The bottom line is that though the reference is set to "Copy Local", its presence in the GAC causes MSBuild to not copy it to the output directory. Here's a great description of the problem and solution. And here's a second post on the subject.

I don't know how long the build and deployment system has had this problem. Probably a long time. There are a few key files, such as Oracle.DataAccess.dll, that get injected into the build process. The deployment scripts package everything and were probably obscuring the issue so that it didn't surface until now. Ultimately the problem is mine since I am the de facto build engineer here. I think that the best course of action is to rebuild the build and deployment environments after this release. There could be other lurking problems like this one that would be discovered by a fresh build server.