Merge pull request #1818 from OctopusDeploy/mergebot/from-release-2026.1-to-main-412305fe8

[Auto-merge from release/2026.1 to main] Merge mergebot/from-release-2026.1-to-main-412305fe8 to main

Author: Octobob

source/Calamari.Common/Features/Scripting/DotnetScript/DotnetScriptBootstrapper.cs

@@ -95,12 +95,13 @@ public static string FindBundledExecutable()
             throw new CommandException(string.Format("dotnet-script was not found at '{0}'", executable));
         }
 
-        public static string FormatCommandArguments(string bootstrapFile, string? scriptParameters)
+        public static string FormatCommandArguments(string bootstrapFile, string? scriptParameters, string? nugetSource = null)
         {
             var (scriptCommandArguments, scriptArguments) = RetrieveParameterValues(scriptParameters);
             var encryptionKey = Convert.ToBase64String(VariableEncryptor.EncryptionKey);
+            var source = string.IsNullOrWhiteSpace(nugetSource) ? "https://api.nuget.org/v3/index.json" : nugetSource;
             var commandArguments = new StringBuilder();
-            commandArguments.Append("-s https://api.nuget.org/v3/index.json ");
+            commandArguments.Append($"-s {source} ");
             if (!string.IsNullOrWhiteSpace(scriptCommandArguments)) commandArguments.Append($"{scriptCommandArguments} ");
             commandArguments.AppendFormat("\"{0}\" -- {1} \"{2}\"", bootstrapFile, scriptArguments, encryptionKey);
             return commandArguments.ToString();

source/Calamari.Common/Features/Scripting/DotnetScript/DotnetScriptExecutor.cs

@@ -32,7 +32,8 @@ protected override IEnumerable<ScriptExecution> PrepareExecution(Script script,
 
             var configurationFile = DotnetScriptBootstrapper.PrepareConfigurationFile(workingDirectory, variables);
             var (bootstrapFile, otherTemporaryFiles) = DotnetScriptBootstrapper.PrepareBootstrapFile(script.File, configurationFile, workingDirectory, variables);
-            var arguments = DotnetScriptBootstrapper.FormatCommandArguments(bootstrapFile, script.Parameters);
+            var nugetSource = variables.Get("Octopus.Action.Script.CSharp.NuGetSource");
+            var arguments = DotnetScriptBootstrapper.FormatCommandArguments(bootstrapFile, script.Parameters, nugetSource);
             bool.TryParse(variables.Get("Octopus.Action.Script.CSharp.BypassIsolation", "false"), out var bypassDotnetScriptIsolation);
 
             var cli = CreateCommandLineInvocation(executable, arguments, !string.IsNullOrWhiteSpace(localDotnetScriptPath));

source/Calamari.Tests/Fixtures/DotnetScript/DotnetScriptBootstrapperFixture.cs

@@ -21,5 +21,15 @@ public void FormatCommandArgumentsTest([CanBeNull] string scriptParameters, [Can
             var formattedCommandArgument = DotnetScriptBootstrapper.FormatCommandArguments(bootstrapFile, scriptParameters);
             formattedCommandArgument.Should().Contain($"{commandArguments}\"{bootstrapFile}\" -- {scriptArguments}");
         }
+
+        [Test]
+        public void FormatCommandArguments_UsesCustomNuGetSource_WhenProvided()
+        {
+            var bootstrapFile = "Bootstrap.csx";
+            var customSource = "https://my.internal.nuget/v3/index.json";
+            var result = DotnetScriptBootstrapper.FormatCommandArguments(bootstrapFile, null, customSource);
+            result.Should().Contain($"-s {customSource} ");
+            result.Should().NotContain("api.nuget.org");
+        }
     }
 }