Illegal characters in path deploying to SharePoint

I recently started doing tests with SharePoint and I reached the point where I needed doing my own WebPart and debug it. I read about setting a development environment for WSS 3.0 in The .NET Addict's Blog: Setting up your SharePoint 2007 Development Environment. Summing up (changing slightly his suggestions), I needed a spare computer or virtual machine to:

• Install Server 2003 R2, with IIS, SP2 and updates
• Install an instance of SQL Server 2005 Standard Edition
• Install Microsoft .NET Framework 3.0 Redistributable Package
• Install Microsoft Windows SharePoint Services 3.0 with Service Pack 1 (WSS3.0SP1) not in standalone mode.
• Install Visual Studio 2005 and Service Pack 1
• Install Microsoft Windows SharePoint Services 3.0: Software Development Kit (SDK)
• Install Microsoft Windows SharePoint Services 3.0 Tools Visual Studio 2005 Extensions
• Install Microsoft Visual Studio 2005 extensions for .NET Framework 3.0 (Windows Workflow Foundation)

After a couple of days I had the virtual environment ready and tried to create my very first Web Part using the Web Part template installed in the previous steps: I just removed a comment so that the Web Part returned "Output HTML":

public class Web_Part1 : System.Web.UI.WebControls.WebParts.WebPart
{
    public Web_Part1()
    {
        this.ExportMode = WebPartExportMode.All;
    }

    protected override void Render(HtmlTextWriter writer)
    {
        // TODO: add custom rendering code here.
        writer.Write("Output HTML");
    }
}

Compiled, tried to deploy... and the following error appeared:

Creating solution ... 
System.ArgumentException 
Illegal characters in path.

No more information, no trace in the EventLog, nor any other log. What path? What character(s)?

I googled for this problem and found a a page that finally drove me in the right direction:

In System.ArgumentException: Illegal characters in path, they talk about Latin characters (my native Operating System, VS2005 and WSS3.0SP1 are Spanish too). They suggest using encoding iso-8859-1 instead of UTF-8 in XML files... but since those files are created by the tools extension add-in (not mine) I could not manage to do any changes there. But they were right in pinpointing that character outside the standard ASCII character set range of 0x00 - 0x7F might be causing the problem.

Even thought his problems were related to a WebService, the idea of the extended characters was interesting. However, none of my files had any of those. I even re-created the simple project and solution right beneath the root C:\ and the problem still appeared: Illegal characters in path.

After some hours I changed the perspective. If VS2005 cannot tell me which file/path has illegal characters, let's do other tool tell me: Process Monitor. For those of you that do not know this tool, Process Monitor is an advanced monitoring tool for Windows that shows real-time file system, Registry and process/thread activity.

I started Process Monitor, filtered by process name devenv.exe (Visual Studio) and tried to do a deploy. Of course it failed again, but then I changed to Process Monitor window and started to scroll and read.

After some minutes I found it! VS2005 was trying to create some files at a temporary directory, pointed by both TMP and TEMP environment variables. They were set to: C:\Documents and settings\myusername\Configuración local\Temp

There was the extended character ó in Configuración. This directory in English systems is: C:\Documents and settings\myusername\Local settings\Temp

After knowing that, all I had to do is changing the user environment variables TMP (and TEMP, just in case) to any other directory not containing any special characters, C:\TEMP for instance. You can do it right clicking on My PC, Properties, Advanced options, Environment variables button, and modify...

I then restarted VS2005 and everything was compiled and deployed without any problem.

Keywords: Visual Studio 2005, VS2005, deploy, WSS3.0, Sharepoint Services, Web Part, development, error, solution, illegal characters in path, caracteres no válidos en la ruta de acceso, implementar