go install fails to find package

```
What steps will reproduce the problem?

1. Installed latest version of go binaries.
2. go install code.google.com/p/codesearch/cmd/cindex (or any other component
library)

This produces:
can't load package: package code.google.com/p/codesearch/cmd/cindex: import
"code.google.com/p/codesearch/cmd/cindex": cannot find package

After that failed, I simply cloned the repository using Hg, and tried to build
locally. Not sure exactly how this is supposed to work (how to install all of
the sources as the local versions of the packages), so whenever I try to build
any sub-folder's contents (with go build), it produces the same error as above
when attempting to locate a dependent package.

What version of the product are you using? On what operating system?

Windows, both 32-bit and 64-bit.

```

Original issue reported on code.google.com by `osman.br...@gmail.com` on 16 May 2012 at 1:13