<pre class="notranslate">$ go version
go version devel +f2e954f463e0 Thu Aug 29 10:16:09 2013 +0200 linux/amd64

steps that will reproduce the problem:
1. $ cd $GOPATH/src
   $ unzip path/to/attached/delfile.zip
2. $ go install delfile
   $ ../bin/delfile
   prints "still there"
3. $ rm delfile/deleted.go
   $ go install delfile
   $ ../bin/delfile
   prints "still there"

the expected output of the second go install is:
# delfile
./main.go:4: undefined: deleted

same behavior is observed for non command/main packages.</pre>
<p dir="auto">Attachments:</p>
<ol dir="auto">
<li><a href="https://storage.googleapis.com/go-attachment/6294/0/delfile.zip" rel="nofollow">delfile.zip</a> (598 bytes)</li>
</ol>
<p dir="auto">by <strong>AndersEdmanXYZ</strong>:</p>
<pre class="notranslate">running go get to fetch pkg from external sources need extra tools to be installed as
listed in <a href="http://code.google.com/p/go-wiki/wiki/GoGetTools" rel="nofollow">http://code.google.com/p/go-wiki/wiki/GoGetTools</a>

Documentation
in <a href="http://golang.org/cmd/go/" rel="nofollow">http://golang.org/cmd/go/</a> description of go get is external tool need not mentioned

error response could be more helpfull: Example:
c:\Go&gt;go get code.google.com/p/draw2d/draw2d
# cd .; hg clone -U <a href="https://code.google.com/p/draw2d" rel="nofollow">https://code.google.com/p/draw2d</a>
C:\Go\src\pkg\code.google.com\p\draw2d
package code.google.com/p/draw2d/draw2d: exec: "hg": executable file not found
in %PATH%

Improved response could mention that needed "hg" is required external sw that
must be installed

Which operating system are you using?
Windows

Which version are you using?  (run 'go version')
1.0.3</pre>