fix: fixed an issue causing lambda package to hang in CI/CD

.autover/changes/e52deae1-471a-4119-b874-5ef0ccf690b3.json

@@ -0,0 +1,11 @@
+{
+  "Projects": [
+    {
+      "Name": "Amazon.Lambda.Tools",
+      "Type": "Patch",
+      "ChangelogMessages": [
+        "Fixed an issue causing 'lambda package' to hang when ran in CI/CD. The fix applies for Linux-based systems."
+      ]
+    }
+  ]
+}

src/Amazon.Lambda.Tools/LambdaDotNetCLIWrapper.cs

@@ -184,42 +184,71 @@ public int Publish(LambdaToolsDefaults defaults, string projectLocation, string
 
             // echo the full dotnet command for debug
             _logger?.WriteLine($"... dotnet {arguments}");
-
-            var psi = new ProcessStartInfo
-            {
-                FileName = dotnetCLI,
-                Arguments = arguments,
-                WorkingDirectory = this._workingDirectory,
-                RedirectStandardOutput = true,
-                RedirectStandardError = true,
-                UseShellExecute = false,
-                CreateNoWindow = true
-            };
-
+            int exitCode;
             var handler = (DataReceivedEventHandler)((o, e) =>
             {
                 if (string.IsNullOrEmpty(e.Data))
                     return;
                 _logger?.WriteLine("... publish: " + e.Data);
             });
-
-            int exitCode;
-            using (var proc = new Process())
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
-                proc.StartInfo = psi;
-                proc.Start();
+                var psi = new ProcessStartInfo
+                {
+                    FileName = dotnetCLI,
+                    Arguments = arguments,
+                    WorkingDirectory = this._workingDirectory,
+                    RedirectStandardOutput = true,
+                    RedirectStandardError = true,
+                    UseShellExecute = false,
+                    CreateNoWindow = true
+                };
+
+                using (var proc = new Process())
+                {
+                    proc.StartInfo = psi;
+                    proc.Start();
 
 
-                proc.ErrorDataReceived += handler;
-                proc.OutputDataReceived += handler;
-                proc.BeginOutputReadLine();
-                proc.BeginErrorReadLine();
+                    proc.ErrorDataReceived += handler;
+                    proc.OutputDataReceived += handler;
+                    proc.BeginOutputReadLine();
+                    proc.BeginErrorReadLine();
 
-                proc.EnableRaisingEvents = true;
+                    proc.EnableRaisingEvents = true;
 
-                proc.WaitForExit();
+                    proc.WaitForExit();
 
-                exitCode = proc.ExitCode;
+                    exitCode = proc.ExitCode;
+                }
+            }
+            else
+            {
+                var tempOutputFile = Path.GetTempFileName();
+                var psi = new ProcessStartInfo
+                {
+                    FileName = GetSystemShell(),
+                    Arguments = $"-c \"{dotnetCLI} {arguments} > '{tempOutputFile}' 2>&1\"",
+                    WorkingDirectory = this._workingDirectory,
+                    UseShellExecute = true,
+                    CreateNoWindow = true
+                };
+
+                using (var proc = new Process())
+                {
+                    proc.StartInfo = psi;
+                    proc.Start();
+
+                    proc.EnableRaisingEvents = true;
+
+                    proc.WaitForExit();
+
+                    var output = File.ReadAllText(tempOutputFile);
+                    _logger?.WriteLine(output);
+                    File.Delete(tempOutputFile);
+
+                    exitCode = proc.ExitCode;
+                }
             }
 
             if (exitCode == 0)
@@ -270,6 +299,25 @@ public int Publish(LambdaToolsDefaults defaults, string projectLocation, string
 
             return exitCode;
         }
+
+        private string GetSystemShell()
+        {
+            if (TryGetEnvironmentVariable("COMSPEC", out var comspec))
+                return comspec!;
+
+            if (TryGetEnvironmentVariable("SHELL", out var shell))
+                return shell!;
+
+            // fall back to defaults
+            return RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? "cmd.exe" : "/bin/sh";
+        }
+
+        private bool TryGetEnvironmentVariable(string variable, out string value)
+        {
+            value = Environment.GetEnvironmentVariable(variable);
+
+            return !string.IsNullOrEmpty(value);
+        }
 
         public string GetPublishArguments(string projectLocation, 
             string outputLocation,