Write output of sign install to log

Actions/Packages.json

@@ -1,5 +1,5 @@
 {
-    "sign": "0.9.1-beta.24123.2",
+    "sign": "0.9.1-beta.24469.1",
     "Microsoft.ApplicationInsights": "2.20.0",
     "Az.Accounts": "2.15.1",
     "Az.Storage": "6.1.1",

Actions/Sign/Sign.psm1

@@ -1,3 +1,15 @@
+<#
+    .SYNOPSIS
+    Checks whether nuget.org is added as a nuget source.
+#>
+function AssertNugetSourceIsAdded() {
+    $nugetSource = "https://api.nuget.org/v3/index.json"
+    $nugetSourceExists = dotnet nuget list source | Select-String -Pattern $nugetSource
+    if (-not $nugetSourceExists) {
+        throw "Nuget source $nugetSource is not added. Please add the source using 'dotnet nuget add source $nugetSource' or add another source with nuget.org as an upstream source."
+    }
+}
+
 <#
     .SYNOPSIS
     Installs the dotnet signing tool.
@@ -16,10 +28,17 @@ function Install-SigningTool() {
     # Install the signing tool in the temp folder
     Write-Host "Installing signing tool version $version in $tempFolder"
     New-Item -ItemType Directory -Path $tempFolder | Out-Null
-    dotnet tool install sign --version $version --tool-path $tempFolder | Out-Null
+    dotnet tool install sign --version $version --tool-path $tempFolder | Out-Host
 
     # Return the path to the signing tool
-    $signingTool = Join-Path -Path $tempFolder "sign.exe" -Resolve
+    $signingTool = Join-Path -Path $tempFolder "sign.exe"
+    if (-not (Test-Path -Path $signingTool)) {
+        # Check if nuget.org is added as a nuget source
+        AssertNugetSourceIsAdded
+
+        # If the tool is not found, throw an error
+        throw "Failed to install signing tool. If you are using a self-hosted runner please make sure you've followed all the steps described in https://aka.ms/algosettings#runs-on."
+    }
     return $signingTool
 }