Fixed a compiler issue on OSX with the creation of a background configuration.

Alamofire.xcodeproj/project.pbxproj

@@ -27,6 +27,8 @@
 		4C33A1441B52089C00873DFF /* ServerTrustPolicyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C33A1421B52089C00873DFF /* ServerTrustPolicyTests.swift */; };
 		4C341BBA1B1A865A00C1B34D /* CacheTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C341BB91B1A865A00C1B34D /* CacheTests.swift */; };
 		4C341BBB1B1A865A00C1B34D /* CacheTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C341BB91B1A865A00C1B34D /* CacheTests.swift */; };
+		4C7C8D221B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C7C8D211B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift */; settings = {ASSET_TAGS = (); }; };
+		4C7C8D231B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C7C8D211B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift */; settings = {ASSET_TAGS = (); }; };
 		4C811F8D1B51856D00E0F59A /* ServerTrustPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C811F8C1B51856D00E0F59A /* ServerTrustPolicy.swift */; };
 		4C811F8E1B51856D00E0F59A /* ServerTrustPolicy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4C811F8C1B51856D00E0F59A /* ServerTrustPolicy.swift */; };
 		4C812C3B1B535F220017E0BF /* alamofire-root-ca.cer in Resources */ = {isa = PBXBuildFile; fileRef = 4C812C3A1B535F220017E0BF /* alamofire-root-ca.cer */; };
@@ -146,6 +148,7 @@
 		4C33A1241B5207DB00873DFF /* unicorn.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = unicorn.png; sourceTree = "<group>"; };
 		4C33A1421B52089C00873DFF /* ServerTrustPolicyTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ServerTrustPolicyTests.swift; sourceTree = "<group>"; };
 		4C341BB91B1A865A00C1B34D /* CacheTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CacheTests.swift; sourceTree = "<group>"; };
+		4C7C8D211B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "NSURLSessionConfiguration+AlamofireTests.swift"; sourceTree = "<group>"; };
 		4C811F8C1B51856D00E0F59A /* ServerTrustPolicy.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ServerTrustPolicy.swift; sourceTree = "<group>"; };
 		4C812C3A1B535F220017E0BF /* alamofire-root-ca.cer */ = {isa = PBXFileReference; lastKnownFileType = file; name = "alamofire-root-ca.cer"; path = "alamofire.org/alamofire-root-ca.cer"; sourceTree = "<group>"; };
 		4C812C3D1B535F2E0017E0BF /* alamofire-signing-ca1.cer */ = {isa = PBXFileReference; lastKnownFileType = file; name = "alamofire-signing-ca1.cer"; path = "alamofire.org/alamofire-signing-ca1.cer"; sourceTree = "<group>"; };
@@ -339,6 +342,14 @@
 			name = "Signed by CA2";
 			sourceTree = "<group>";
 		};
+		4C7C8D201B9D0D7300948136 /* Extensions */ = {
+			isa = PBXGroup;
+			children = (
+				4C7C8D211B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift */,
+			);
+			name = Extensions;
+			sourceTree = "<group>";
+		};
 		4C812C381B535F000017E0BF /* disig.sk */ = {
 			isa = PBXGroup;
 			children = (
@@ -431,6 +442,7 @@
 			children = (
 				4C256A501B096C2C0065714F /* BaseTestCase.swift */,
 				4C256A4E1B09656A0065714F /* Core */,
+				4C7C8D201B9D0D7300948136 /* Extensions */,
 				4C256A4F1B09656E0065714F /* Features */,
 				4C3238E91B3617A600FE04AE /* Resources */,
 				F8111E4019A95C8B0040E7D1 /* Supporting Files */,
@@ -764,6 +776,7 @@
 				F8111E6119A9674D0040E7D1 /* ParameterEncodingTests.swift in Sources */,
 				F8111E6419A9674D0040E7D1 /* UploadTests.swift in Sources */,
 				F8111E6019A9674D0040E7D1 /* DownloadTests.swift in Sources */,
+				4C7C8D221B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -787,6 +800,7 @@
 				F829C6C41A7A950600A2CD59 /* AuthenticationTests.swift in Sources */,
 				F829C6C51A7A950600A2CD59 /* ValidationTests.swift in Sources */,
 				F86AEFE81AE6A315007D9C76 /* TLSEvaluationTests.swift in Sources */,
+				4C7C8D231B9D0D9000948136 /* NSURLSessionConfiguration+AlamofireTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Tests/ManagerTests.swift

@@ -124,16 +124,7 @@ class ManagerConfigurationHeadersTestCase: BaseTestCase {
                     configuration = NSURLSessionConfiguration.ephemeralSessionConfiguration()
                 case .Background:
                     let identifier = "com.alamofire.test.manager-configuration-tests"
-
-                    #if os(iOS) || os(watchOS)
-                        configuration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(identifier)
-                    #else
-                        if #available(OSX 10.10, *) {
-                            configuration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(identifier)
-                        } else {
-                            configuration = NSURLSessionConfiguration.backgroundSessionConfiguration(identifier)
-                        }
-                    #endif
+                    configuration = NSURLSessionConfiguration.backgroundSessionConfigurationForAllPlatformsWithIdentifier(identifier)
                 }
 
                 var headers = Alamofire.Manager.defaultHTTPHeaders

Tests/NSURLSessionConfiguration+AlamofireTests.swift

+// NSURLSessionConfiguration+AlamofireTests.swift
+//
+// Copyright (c) 2014–2015 Alamofire Software Foundation (http://alamofire.org/)
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+import Foundation
+
+extension NSURLSessionConfiguration {
+    static func backgroundSessionConfigurationForAllPlatformsWithIdentifier(identifier: String) -> NSURLSessionConfiguration {
+        let configuration: NSURLSessionConfiguration
+
+        #if os(iOS) || os(watchOS)
+            configuration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(identifier)
+        #else
+            if #available(OSX 10.10, *) {
+                configuration = NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(identifier)
+            } else {
+                configuration = NSURLSessionConfiguration.backgroundSessionConfiguration(identifier)
+            }
+        #endif
+
+        return configuration
+    }
+}

Tests/UploadTests.swift

@@ -585,12 +585,12 @@ class UploadMultipartFormDataTestCase: BaseTestCase {
 
     func testThatUploadingMultipartFormDataOnBackgroundSessionWritesDataToFileToAvoidCrash() {
         // Given
-        let identifier = "com.alamofire.uploadtests.\(NSUUID().UUIDString)"
+        let manager: Manager = {
+            let identifier = "com.alamofire.uploadtests.\(NSUUID().UUIDString)"
+            let configuration = NSURLSessionConfiguration.backgroundSessionConfigurationForAllPlatformsWithIdentifier(identifier)
 
-        let manager = Manager(
-            configuration: NSURLSessionConfiguration.backgroundSessionConfigurationWithIdentifier(identifier),
-            serverTrustPolicyManager: nil
-        )
+            return Manager(configuration: configuration, serverTrustPolicyManager: nil)
+        }()
 
         let URLString = "https://httpbin.org/post"
         let french = "français".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!