diff --git a/src/mono/wasm/Wasm.Build.Tests/BlazorWasmBuildPublishTests.cs b/src/mono/wasm/Wasm.Build.Tests/BlazorWasmBuildPublishTests.cs
index a3f250b462394c..39f7dfba8587ff 100644
--- a/src/mono/wasm/Wasm.Build.Tests/BlazorWasmBuildPublishTests.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/BlazorWasmBuildPublishTests.cs
@@ -241,6 +241,7 @@ public void BugRegression_60479_WithRazorClassLib()
             Directory.CreateDirectory(wasmProjectDir);
             new DotNetCommand(s_buildEnv, _testOutput, useDefaultArgs: false)
                     .WithWorkingDirectory(wasmProjectDir)
+                    .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                     .ExecuteWithCapturedOutput("new blazorwasm")
                     .EnsureSuccessful();
 
@@ -249,6 +250,7 @@ public void BugRegression_60479_WithRazorClassLib()
             Directory.CreateDirectory(razorProjectDir);
             new DotNetCommand(s_buildEnv, _testOutput, useDefaultArgs: false)
                     .WithWorkingDirectory(razorProjectDir)
+                    .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                     .ExecuteWithCapturedOutput("new razorclasslib")
                     .EnsureSuccessful();
 
diff --git a/src/mono/wasm/Wasm.Build.Tests/BlazorWasmTests.cs b/src/mono/wasm/Wasm.Build.Tests/BlazorWasmTests.cs
index cfb725bd59f22a..91cf6c23156fe0 100644
--- a/src/mono/wasm/Wasm.Build.Tests/BlazorWasmTests.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/BlazorWasmTests.cs
@@ -61,6 +61,7 @@ private CommandResult PublishForRequiresWorkloadTest(string config, string extra
             string publishLogPath = Path.Combine(s_buildEnv.LogRootPath, id, $"{id}.binlog");
             return new DotNetCommand(s_buildEnv, _testOutput)
                             .WithWorkingDirectory(_projectDir!)
+                            .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                             .ExecuteWithCapturedOutput("publish",
                                                         $"-bl:{publishLogPath}",
                                                         $"-p:Configuration={config}");
@@ -109,6 +110,7 @@ private void BuildNet50Project(string config, bool aot, bool expectError, string
             string publishLogPath = Path.Combine(logPath, $"{id}.binlog");
             CommandResult result = new DotNetCommand(s_buildEnv, _testOutput)
                                             .WithWorkingDirectory(_projectDir!)
+                                            .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                                             .ExecuteWithCapturedOutput("publish",
                                                                        $"-bl:{publishLogPath}",
                                                                        (aot ? "-p:RunAOTCompilation=true" : ""),
diff --git a/src/mono/wasm/Wasm.Build.Tests/BuildTestBase.cs b/src/mono/wasm/Wasm.Build.Tests/BuildTestBase.cs
index f4a73bdbb0fe5b..d427f1d1f348d9 100644
--- a/src/mono/wasm/Wasm.Build.Tests/BuildTestBase.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/BuildTestBase.cs
@@ -36,6 +36,7 @@ public abstract class BuildTestBase : IClassFixture<SharedBuildPerTestClassFixtu
         protected string _logPath;
         protected bool _enablePerTestCleanup = false;
         protected SharedBuildPerTestClassFixture _buildContext;
+        protected string _nugetPackagesDir = string.Empty;
 
         // FIXME: use an envvar to override this
         protected static int s_defaultPerTestTimeoutMs = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? 30*60*1000 : 15*60*1000;
@@ -63,13 +64,6 @@ static BuildTestBase()
                 else
                     s_xharnessRunnerCommand = EnvironmentVariables.XHarnessCliPath;
 
-                string? nugetPackagesPath = Environment.GetEnvironmentVariable("NUGET_PACKAGES");
-                if (!string.IsNullOrEmpty(nugetPackagesPath))
-                {
-                    if (!Directory.Exists(nugetPackagesPath))
-                        Directory.CreateDirectory(nugetPackagesPath);
-                }
-
                 Console.WriteLine ("");
                 Console.WriteLine ($"==============================================================================================");
                 Console.WriteLine ($"=============== Running with {(s_buildEnv.IsWorkload ? "Workloads" : "No workloads")} ===============");
@@ -286,7 +280,12 @@ protected void InitPaths(string id)
             if (_projectDir == null)
                 _projectDir = Path.Combine(AppContext.BaseDirectory, id);
             _logPath = Path.Combine(s_buildEnv.LogRootPath, id);
+            _nugetPackagesDir = Path.Combine(BuildEnvironment.TmpPath, "nuget", id);
+
+            if (Directory.Exists(_nugetPackagesDir))
+                Directory.Delete(_nugetPackagesDir, recursive: true);
 
+            Directory.CreateDirectory(_nugetPackagesDir!);
             Directory.CreateDirectory(_logPath);
         }
 
@@ -405,6 +404,7 @@ protected static BuildArgs ExpandBuildArgs(BuildArgs buildArgs, string extraProp
                     foreach (var kvp in options.ExtraBuildEnvironmentVariables!)
                         envVars[kvp.Key] = kvp.Value;
                 }
+                envVars["NUGET_PACKAGES"] = _nugetPackagesDir;
                 result = AssertBuild(sb.ToString(), id, expectSuccess: options.ExpectSuccess, envVars: envVars);
 
                 // check that we are using the correct runtime pack!
@@ -487,6 +487,7 @@ public string CreateBlazorWasmTemplateProject(string id)
             InitBlazorWasmProjectDir(id);
             new DotNetCommand(s_buildEnv, _testOutput, useDefaultArgs: false)
                     .WithWorkingDirectory(_projectDir!)
+                    .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                     .ExecuteWithCapturedOutput("new blazorwasm")
                     .EnsureSuccessful();
 
diff --git a/src/mono/wasm/Wasm.Build.Tests/CleanTests.cs b/src/mono/wasm/Wasm.Build.Tests/CleanTests.cs
index bbd0f0106e89bd..6be1a736ce1409 100644
--- a/src/mono/wasm/Wasm.Build.Tests/CleanTests.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/CleanTests.cs
@@ -42,6 +42,7 @@ public void Blazor_BuildThenClean_NativeRelinking(string config)
         string logPath = Path.Combine(s_buildEnv.LogRootPath, id, $"{id}-clean.binlog");
         new DotNetCommand(s_buildEnv, _testOutput)
                 .WithWorkingDirectory(_projectDir!)
+                .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                 .ExecuteWithCapturedOutput("build", "-t:Clean", $"-p:Configuration={config}", $"-bl:{logPath}")
                 .EnsureSuccessful();
 
@@ -89,6 +90,7 @@ private void Blazor_BuildNativeNonNative_ThenCleanTest(string config, bool first
         string logPath = Path.Combine(s_buildEnv.LogRootPath, id, $"{id}-clean.binlog");
         new DotNetCommand(s_buildEnv, _testOutput)
                 .WithWorkingDirectory(_projectDir!)
+                .WithEnvironmentVariable("NUGET_PACKAGES", _projectDir!)
                 .ExecuteWithCapturedOutput("build", "-t:Clean", $"-p:Configuration={config}", $"-bl:{logPath}")
                 .EnsureSuccessful();
 
diff --git a/src/mono/wasm/Wasm.Build.Tests/NativeBuildTests.cs b/src/mono/wasm/Wasm.Build.Tests/NativeBuildTests.cs
index 9c8b7c03204f98..3b9d62d69f1b28 100644
--- a/src/mono/wasm/Wasm.Build.Tests/NativeBuildTests.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/NativeBuildTests.cs
@@ -123,6 +123,7 @@ public void BlazorWasm_CanRunMonoAOTCross_WithNoTrimming(string config)
             string publishLogPath = Path.Combine(s_buildEnv.LogRootPath, id, $"{id}.binlog");
             CommandResult res = new DotNetCommand(s_buildEnv, _testOutput)
                                         .WithWorkingDirectory(_projectDir!)
+                                        .WithEnvironmentVariable("NUGET_PACKAGES", _nugetPackagesDir)
                                         .ExecuteWithCapturedOutput("publish",
                                                                    $"-bl:{publishLogPath}",
                                                                    "-p:RunAOTCompilation=true",
diff --git a/src/mono/wasm/Wasm.Build.Tests/RunCommand.cs b/src/mono/wasm/Wasm.Build.Tests/RunCommand.cs
index 33759316d1e34f..d7baa51e2c1139 100644
--- a/src/mono/wasm/Wasm.Build.Tests/RunCommand.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/RunCommand.cs
@@ -10,6 +10,7 @@ public class RunCommand : DotNetCommand
 {
     public RunCommand(BuildEnvironment buildEnv, ITestOutputHelper _testOutput, string label="") : base(buildEnv, _testOutput, false, label)
     {
+        WithEnvironmentVariables(buildEnv.EnvVars);
         WithEnvironmentVariable("DOTNET_ROOT", buildEnv.DotNet);
         WithEnvironmentVariable("DOTNET_INSTALL_DIR", Path.GetDirectoryName(buildEnv.DotNet)!);
         WithEnvironmentVariable("DOTNET_MULTILEVEL_LOOKUP", "0");
diff --git a/src/mono/wasm/Wasm.Build.Tests/ToolCommand.cs b/src/mono/wasm/Wasm.Build.Tests/ToolCommand.cs
index 8526f0d63b551c..a3438f707c4d21 100644
--- a/src/mono/wasm/Wasm.Build.Tests/ToolCommand.cs
+++ b/src/mono/wasm/Wasm.Build.Tests/ToolCommand.cs
@@ -79,7 +79,7 @@ public async virtual Task<CommandResult> ExecuteAsync(params string[] args)
         {
             var resolvedCommand = _command;
             string fullArgs = GetFullArgs(args);
-            _testOutput.WriteLine($"[{_label}] Executing - {resolvedCommand} {fullArgs} - {WorkingDirectoryInfo()}");
+            _testOutput.WriteLine($"[{_label}] Executing - {resolvedCommand} {fullArgs} {WorkingDirectoryInfo()}");
             return await ExecuteAsyncInternal(resolvedCommand, fullArgs);
         }