How do I set specific environment variables when debugging in Visual Studio?

Question

On a class library project, I set the "Start Action" on the Debug tab of the project properties to "Start external program" (NUnit in this case). I want to set an environment variable in the environment this program is started in. How do I do that? (Is it even possible?)

EDIT:

It's an environment variable that influences all .NET applications (COMplus_Version, it sets the runtime version) so setting it system wide really isn't an option.

As a workaround I just forced NUnit to start in right .NET version (2.0) by setting it in nunit.exe.config, though unfortunately this also means all my .NET 1.1 unit tests are now also run in .NET 2.0. I should probably just make a copy of the executable so it can have its own configuration file...

(I am keeping the question open (not accepting an answer) in case someone does happen to find out how (it might be useful for other purposes too after all...))

Diminish

Do you want an environment variable specifically for this one program only? – Myalgia

Answer 1

In Visual Studio 2008 and Visual Studio 2005 at least, you can specify changes to environment variables in the project settings.

Open your project. Go to Project -> Properties... Under Configuration Properties -> Debugging, edit the 'Environment' value to set environment variables.

For example, if you want to add the directory "c:\foo\bin" to the path when debugging your application, set the 'Environment' value to "PATH=%PATH%;c:\foo\bin".

Diffidence

I'm using VS2008, and my project properties doesn't have "Configuration Properties" or "Debugging" on it. I can't find anything about environment variables anywhere under the project properties. What am I doing wrong? – Floccose

I will edit this post with a screenshot of where the settings are. – Diffidence

Hi, how did you get to this screen? In my VS2008 and VS2005 project properties seem to look differently, and they don't have environment settings – Blastoff

This is properties for C/C++ projects. I guess you are using C# or VB.NET – Dollfuss

Hi, all. I noticed that several of my developers, who all work in C++, also could not see these properties. In the end it turned out to be how MSVC was installed. When they reinstalled MSVC with every option enabled, they were able to see all these properties, along with other IDE functionality. – Diffidence

sadly, this is not available for remote debugging. – Armallas

Also doesn't seem to be available for Web projects. – Larner

There is a bug which forbids to add several variables. See workaround in : connect.microsoft.com/VisualStudio/feedback/details/739477/… – Blowzed

Nothing remotely similar to this in VS2017 – Selectee

Be careful not to have any spaces before or after any sign like the = or the ; !!!! It took me 2 hours to find it. – Millur

For those struggling to find the "Properties" pane, you can right-click the solution in the Solution Explorer. It will be at the end of the list. – Preemie

Answer 2

In Visual Studio 2019 right-click your project, choose Properties. In the project properties window, select the Debug tab. Then, under Environment variables change the value of your environment from Development to Production or other environments. For .Net Core and .Net 5 the property is called ASPNETCORE_ENVIRONMENT.

Anaemia

Pretty sure this only works for .Net Core|5+ because my Debug tab doesn't have that Environment variables stuff at all. Or perhaps it's a Console App vs. WebSite|WebAPI thing? – Russon

@ScottFraley The example was through an ASP .NET Core 5 project – Anaemia

@WouterVanherck yes, but the OP (14 yrs ago) was asking about a .NET Framework project or solution, .NET Core | 5+ did not exist yet. And it is going to affect the answer. – Osbourne

Answer 3

In Visual Studio for Mac and C# you can use:

Environment.SetEnvironmentVariable("<Variable_name>", "<Value>");

But you will need the following namespace

using System.Collections;

you can check the full list of variables with this:

foreach (DictionaryEntry de in Environment.GetEnvironmentVariables())
{
    Console.WriteLine("  {0} = {1}", de.Key, de.Value);
}

Diomedes

OMG, I've been searching for the last half hour to find that simple call Environment.SetEnvironmentVariable(). Thanks! – Rhinoceros

This explains how to set an environment variable globally from code. The question explicitly mentions this as undesireable. – Bohon

Hey I'd love to try this! Could someone let me know how to set it up or where I need to put it? – Milner

Answer 4

Visual Studio 2003 doesn't seem to allow you to set environment variables for debugging.

What I do in C/C++ is use _putenv() in main() and set any variables. Usually I surround it with a #if defined DEBUG_MODE / #endif to make sure only certain builds have it.

_putenv("MYANSWER=42");

I believe you can do the same thing with C# using os.putenv(), i.e.

os.putenv('MYANSWER', '42');

These will set the envrironment variable for that shell process only, and as such is an ephemeral setting, which is what you are looking for.

By the way, its good to use process explorer (http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx), which is a sysinternals tool. You can see what a given process' copy of the environment variables is, so you can validate that what you set is what you got.

Chromatogram

Answer 5

In VS 2022 for .NET 5 and 6 you can set environment variables under properties of project -> Debug -> under General click on 'Open debug launch profiles UI' and scroll down to 'Environment variables'

Ceric

Answer 6

Starting with NUnit 2.5 you can use /framework switch e.g.:

nunit-console myassembly.dll /framework:net-1.1

This is from NUnit's help pages.

Irrepressible

Answer 7

In Visual Studio 2022, go to solution explorer, right click to project file. Then, click on the Debug link at the left side. Then, click on the Open debug and launch profiles UI. Then, you can add new variables into the field in Environment Variables section. Environment Variables

Musicianship

Answer 8

If you are using VS 2019, Go to Project-> Properties->Debug. check here

Add key and value for your variables. Then it is done. Check launchSettings.json in properties folder you should see your variable there.

Astoria

Answer 9

Set up a batch file which you can invoke. Pass the path the batch file, and have the batch file set the environment variable and then invoke NUnit.

Lizbeth

Visual Studio refuses to accept anything but executables (.exe) in the path for the program to start. – Diminish

Answer 10

As environments are inherited from the parent process, you could write an add-in for Visual Studio that modifies its environment variables before you perform the start. I am not sure how easy that would be to put into your process.

Shiller

Answer 11

I prefer to keep all such definitions in the make files, i.e. in the .*proj or .props - because these are under SCM. I avoid the VS-Gui-Property-Dialogs. A lot of the config you write there goes into some .user, .suo or so, which is usually not under SCM.
E.g. in case of environment variables you could write (using a text editor) something like the following in your .vcxproj:

<PropertyGroup>
  <LocalDebuggerEnvironment Condition="'$(Configuration)'=='Debug'">
ANSWER=42
RUNTIME_DIR="$(g_runtime_dir)"
COLOR=octarin
  </LocalDebuggerEnvironment>
</PropertyGroup>

NOTE that you can use MSBuild Conditions and other build properties to define the environment variables.

NOTE: this works for me with VS2013 and VS2019. I think it is the same for other VS + MSBuild versions.

Xenocrates

Answer 12

If you can't use bat files to set up your environment, then your only likely option is to set up a system wide environment variable. You can find these by doing

1. Right click "My Computer"
2. Select properties
3. Select the "advanced" tab
4. Click the "environment variables" button
5. In the "System variables" section, add the new environment variable that you desire
6. "Ok" all the way out to accept your changes

I don't know if you'd have to restart visual studio, but seems unlikely. HTH

Qr

Mark, I believe the requirement was for the environment the program was started in, not the user or system environments. – Lizbeth

Yeah, it's an environment variable that influences all .NET apps (COMplus_Version, it sets runtime version) so setting it system wide really isn't an option. – Diminish

I got thru by defining a user-level Environment variable (My Computer > Properties > Advanced). Launch a new instance of the command shell and echo %NEW_VAR% just to be sure. Start a new instance of devenv and debug away. – Ubald

Answer 13

You can set it at Property > Configuration Properties > Debugging > Environment

Scribe

Did you even tested that before posting the answer? I guess not. -1. – Histoid

The only mistake in this answer is that "set" is not needed – Sentinel