From 6661903b189505602b51c2aae8c0d6bda95cb3c7 Mon Sep 17 00:00:00 2001
From: Marc Prud'hommeaux <mwp1@cornell.edu>
Date: Wed, 13 Aug 2025 17:11:42 -0400
Subject: [PATCH] Linux support

---
 .github/workflows/ci.yml                             |  3 +++
 Tests/SkipFoundationTests/CoreLibs/TestDecimal.swift |  2 +-
 .../Formats/TestAttributedString.swift               |  2 +-
 .../Formats/TestAttributedStringPerformance.swift    |  2 +-
 .../Formats/TestXMLDocument.swift                    |  3 +++
 .../SkipFoundationTests/Formats/TestXMLParser.swift  |  3 +++
 .../Formatters/TestRelativeDateTimeFormatter.swift   |  4 ++++
 .../SkipFoundationTests/Foundation/BundleTests.swift |  5 +----
 Tests/SkipFoundationTests/Foundation/DateTests.swift |  3 +++
 .../SkipFoundationTests/Foundation/DigestTests.swift |  2 ++
 Tests/SkipFoundationTests/Foundation/JSONTests.swift |  3 ---
 .../SkipFoundationTests/Foundation/LocaleTests.swift |  4 ++++
 .../SkipFoundationTests/Foundation/LoggerTests.swift |  2 ++
 .../Network/TestCachedURLResponse.swift              |  3 +++
 .../Network/TestDataURLProtocol.swift                |  3 +++
 .../SkipFoundationTests/Network/TestHTTPCookie.swift |  3 +++
 .../Network/TestHTTPCookieStorage.swift              |  3 +++
 .../Network/TestHTTPURLResponse.swift                |  3 +++
 Tests/SkipFoundationTests/Network/TestHost.swift     |  3 +++
 .../SkipFoundationTests/Network/TestSocketPort.swift |  3 +++
 Tests/SkipFoundationTests/Network/TestURL.swift      |  3 +++
 Tests/SkipFoundationTests/Network/TestURLCache.swift |  3 +++
 .../Network/TestURLComponents.swift                  |  3 +++
 .../Network/TestURLCredential.swift                  |  3 +++
 .../Network/TestURLCredentialStorage.swift           |  3 +++
 .../Network/TestURLProtectionSpace.swift             |  3 +++
 .../SkipFoundationTests/Network/TestURLRequest.swift |  3 +++
 .../Network/TestURLResponse.swift                    |  3 +++
 .../SkipFoundationTests/Network/TestURLSession.swift |  7 +++++++
 Tests/SkipFoundationTests/SkipFoundationTests.swift  |  6 ++++++
 .../System/TestNotificationCenter.swift              |  4 ++++
 Tests/SkipFoundationTests/System/TestThread.swift    | 12 ++++++++++++
 Tests/SkipFoundationTests/XCSkipTests.swift          |  2 +-
 33 files changed, 103 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e476c69..ba7da9d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,3 +14,6 @@ permissions:
 jobs:
   call-workflow:
     uses: skiptools/actions/.github/workflows/skip-framework.yml@v1
+    with:
+      runs-on: "['macos-13', 'ubuntu-24.04']"
+
diff --git a/Tests/SkipFoundationTests/CoreLibs/TestDecimal.swift b/Tests/SkipFoundationTests/CoreLibs/TestDecimal.swift
index 6890350..df8d69d 100644
--- a/Tests/SkipFoundationTests/CoreLibs/TestDecimal.swift
+++ b/Tests/SkipFoundationTests/CoreLibs/TestDecimal.swift
@@ -3,7 +3,7 @@
 import Foundation
 import XCTest
 
-#if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
+#if !SKIP && canImport(Darwin) // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
 
diff --git a/Tests/SkipFoundationTests/Formats/TestAttributedString.swift b/Tests/SkipFoundationTests/Formats/TestAttributedString.swift
index 6d0750e..828ba99 100644
--- a/Tests/SkipFoundationTests/Formats/TestAttributedString.swift
+++ b/Tests/SkipFoundationTests/Formats/TestAttributedString.swift
@@ -3,7 +3,7 @@
 import Foundation
 import XCTest
 
-#if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
+#if !SKIP && canImport(Darwin) // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
 
diff --git a/Tests/SkipFoundationTests/Formats/TestAttributedStringPerformance.swift b/Tests/SkipFoundationTests/Formats/TestAttributedStringPerformance.swift
index 671f01c..853b5de 100644
--- a/Tests/SkipFoundationTests/Formats/TestAttributedStringPerformance.swift
+++ b/Tests/SkipFoundationTests/Formats/TestAttributedStringPerformance.swift
@@ -3,7 +3,7 @@
 import Foundation
 import XCTest
 
-#if !SKIP
+#if canImport(Darwin)
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
 
 //===----------------------------------------------------------------------===//
diff --git a/Tests/SkipFoundationTests/Formats/TestXMLDocument.swift b/Tests/SkipFoundationTests/Formats/TestXMLDocument.swift
index b95700a..0af5396 100644
--- a/Tests/SkipFoundationTests/Formats/TestXMLDocument.swift
+++ b/Tests/SkipFoundationTests/Formats/TestXMLDocument.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationXML)
+import FoundationXML
+#endif
 import XCTest
 
 #if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
diff --git a/Tests/SkipFoundationTests/Formats/TestXMLParser.swift b/Tests/SkipFoundationTests/Formats/TestXMLParser.swift
index 833aabd..ce115d2 100644
--- a/Tests/SkipFoundationTests/Formats/TestXMLParser.swift
+++ b/Tests/SkipFoundationTests/Formats/TestXMLParser.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationXML)
+import FoundationXML
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Formatters/TestRelativeDateTimeFormatter.swift b/Tests/SkipFoundationTests/Formatters/TestRelativeDateTimeFormatter.swift
index d2f6235..b2e9484 100644
--- a/Tests/SkipFoundationTests/Formatters/TestRelativeDateTimeFormatter.swift
+++ b/Tests/SkipFoundationTests/Formatters/TestRelativeDateTimeFormatter.swift
@@ -3,6 +3,8 @@
 import Foundation
 import XCTest
 
+#if SKIP || canImport(Darwin)
+
 fileprivate typealias CaseRelativeFormat = (numericFull: String, namedShort: String, namedAbbreviated: String, dateComponents: DateComponents, timeInterval: TimeInterval)
 
 /// Kotlin formats time intervals approaching/at 0 as "x ago"
@@ -297,3 +299,5 @@ class TestRelativeDateTimeFormatter: XCTestCase {
         return (timeInterval, components, formattedString)
     }
 }
+
+#endif
diff --git a/Tests/SkipFoundationTests/Foundation/BundleTests.swift b/Tests/SkipFoundationTests/Foundation/BundleTests.swift
index a32507b..1a7baad 100644
--- a/Tests/SkipFoundationTests/Foundation/BundleTests.swift
+++ b/Tests/SkipFoundationTests/Foundation/BundleTests.swift
@@ -1,19 +1,16 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
-import OSLog
 import XCTest
 
 @available(macOS 13, iOS 16, watchOS 10, tvOS 16, *)
 final class BundleTests: XCTestCase {
-    let logger: Logger = Logger(subsystem: "test", category: "BundleTests")
-
     func testBundle() throws {
         // Swift will be: Contents/Resources/ -- file:///~/Library/Developer/Xcode/DerivedData/DemoApp-ABCDEF/Build/Products/Debug/SkipFoundationTests.xctest/Contents/Resources/Skip_SkipFoundationTests.bundle/
         // Kotlin will be: file:///~/Library/Developer/Xcode/DerivedData/DemoApp-ABCDEF/Build/Products/Debug/SkipFoundationTests.xctest/Contents/Resources/skip-foundation_SkipFoundationTests.bundle/Contents/Resources/textasset.txt
 
         let resourceURL: URL = try XCTUnwrap(Bundle.module.url(forResource: "textasset", withExtension: "txt", subdirectory: nil, localization: nil))
-        logger.info("resourceURL: \(resourceURL.absoluteString)")
+        //logger.info("resourceURL: \(resourceURL.absoluteString)")
         let str = try String(contentsOf: resourceURL)
         XCTAssertEqual("Some text\n", str)
     }
diff --git a/Tests/SkipFoundationTests/Foundation/DateTests.swift b/Tests/SkipFoundationTests/Foundation/DateTests.swift
index cd54bff..80b50f6 100644
--- a/Tests/SkipFoundationTests/Foundation/DateTests.swift
+++ b/Tests/SkipFoundationTests/Foundation/DateTests.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(CoreFoundation)
+import CoreFoundation // for CFAbsoluteTimeGetCurrent()
+#endif
 import XCTest
 
 @available(macOS 12, iOS 15, tvOS 15, watchOS 8, *)
diff --git a/Tests/SkipFoundationTests/Foundation/DigestTests.swift b/Tests/SkipFoundationTests/Foundation/DigestTests.swift
index f08b694..18a4a2a 100644
--- a/Tests/SkipFoundationTests/Foundation/DigestTests.swift
+++ b/Tests/SkipFoundationTests/Foundation/DigestTests.swift
@@ -13,6 +13,7 @@ extension Data {
 }
 #endif
 
+#if SKIP || canImport(CryptoKit) // i.e., not Linux
 @available(macOS 11, iOS 14, watchOS 7, tvOS 14, *)
 final class DigestTests: XCTestCase {
     func testSHA256() {
@@ -93,4 +94,5 @@ final class DigestTests: XCTestCase {
         XCTAssertEqual("TrfwQeSZQ8gTfY7U+NQY+CDxexfk6hHVDJ2pevtMM2OXmxY9X/60uWhsXnMym1+vzg7XGgO729yGQgsPdAY19A==", Data(HMACSHA512.authenticationCode(for: Data("Your message to sign".utf8), using: SymmetricKey(data: Data("your-secret-key".utf8)))).base64EncodedString())
     }
 }
+#endif
 
diff --git a/Tests/SkipFoundationTests/Foundation/JSONTests.swift b/Tests/SkipFoundationTests/Foundation/JSONTests.swift
index 5ec642c..49391c9 100644
--- a/Tests/SkipFoundationTests/Foundation/JSONTests.swift
+++ b/Tests/SkipFoundationTests/Foundation/JSONTests.swift
@@ -1,13 +1,10 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
-import OSLog
 import XCTest
 import Foundation
 
 @available(macOS 11, iOS 14, watchOS 7, tvOS 14, *)
 class TestJSON : XCTestCase {
-    fileprivate let logger: Logger = Logger(subsystem: "test", category: "TestJSON")
-
     struct StringField : Equatable, Codable {
         var stringField: String
     }
diff --git a/Tests/SkipFoundationTests/Foundation/LocaleTests.swift b/Tests/SkipFoundationTests/Foundation/LocaleTests.swift
index f979f5b..fc1d8f8 100644
--- a/Tests/SkipFoundationTests/Foundation/LocaleTests.swift
+++ b/Tests/SkipFoundationTests/Foundation/LocaleTests.swift
@@ -3,6 +3,8 @@
 import Foundation
 import XCTest
 
+#if SKIP || canImport(Darwin)
+
 @available(macOS 13, iOS 16, watchOS 10, tvOS 16, *)
 final class LocaleTests: XCTestCase {
     func testLanguageCodes() throws {
@@ -1051,3 +1053,5 @@ let xcstringsSample = """
 }
 
 """
+#endif
+
diff --git a/Tests/SkipFoundationTests/Foundation/LoggerTests.swift b/Tests/SkipFoundationTests/Foundation/LoggerTests.swift
index f179167..21a1c85 100644
--- a/Tests/SkipFoundationTests/Foundation/LoggerTests.swift
+++ b/Tests/SkipFoundationTests/Foundation/LoggerTests.swift
@@ -1,5 +1,6 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
+#if SKIP || canImport(OSLog)
 import OSLog
 import XCTest
 
@@ -24,3 +25,4 @@ final class LoggerTests: XCTestCase {
         logger.error("logger error test")
     }
 }
+#endif
diff --git a/Tests/SkipFoundationTests/Network/TestCachedURLResponse.swift b/Tests/SkipFoundationTests/Network/TestCachedURLResponse.swift
index b1c5bdc..c310829 100644
--- a/Tests/SkipFoundationTests/Network/TestCachedURLResponse.swift
+++ b/Tests/SkipFoundationTests/Network/TestCachedURLResponse.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestDataURLProtocol.swift b/Tests/SkipFoundationTests/Network/TestDataURLProtocol.swift
index d50b83c..a4d9563 100644
--- a/Tests/SkipFoundationTests/Network/TestDataURLProtocol.swift
+++ b/Tests/SkipFoundationTests/Network/TestDataURLProtocol.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestHTTPCookie.swift b/Tests/SkipFoundationTests/Network/TestHTTPCookie.swift
index 8aa1178..918de6a 100644
--- a/Tests/SkipFoundationTests/Network/TestHTTPCookie.swift
+++ b/Tests/SkipFoundationTests/Network/TestHTTPCookie.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 #if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
diff --git a/Tests/SkipFoundationTests/Network/TestHTTPCookieStorage.swift b/Tests/SkipFoundationTests/Network/TestHTTPCookieStorage.swift
index 3c0a0b4..5e2bee9 100644
--- a/Tests/SkipFoundationTests/Network/TestHTTPCookieStorage.swift
+++ b/Tests/SkipFoundationTests/Network/TestHTTPCookieStorage.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 #if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
diff --git a/Tests/SkipFoundationTests/Network/TestHTTPURLResponse.swift b/Tests/SkipFoundationTests/Network/TestHTTPURLResponse.swift
index 9052fbf..7e346f1 100644
--- a/Tests/SkipFoundationTests/Network/TestHTTPURLResponse.swift
+++ b/Tests/SkipFoundationTests/Network/TestHTTPURLResponse.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestHost.swift b/Tests/SkipFoundationTests/Network/TestHost.swift
index af50f87..7db0d57 100644
--- a/Tests/SkipFoundationTests/Network/TestHost.swift
+++ b/Tests/SkipFoundationTests/Network/TestHost.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestSocketPort.swift b/Tests/SkipFoundationTests/Network/TestSocketPort.swift
index 8b67f62..c9149ed 100644
--- a/Tests/SkipFoundationTests/Network/TestSocketPort.swift
+++ b/Tests/SkipFoundationTests/Network/TestSocketPort.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 #if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
diff --git a/Tests/SkipFoundationTests/Network/TestURL.swift b/Tests/SkipFoundationTests/Network/TestURL.swift
index acf4c82..13ec580 100644
--- a/Tests/SkipFoundationTests/Network/TestURL.swift
+++ b/Tests/SkipFoundationTests/Network/TestURL.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // TODO: remove '// API marked unavailable for Skip:' portions as we make more API available
diff --git a/Tests/SkipFoundationTests/Network/TestURLCache.swift b/Tests/SkipFoundationTests/Network/TestURLCache.swift
index 7821e61..ea425aa 100644
--- a/Tests/SkipFoundationTests/Network/TestURLCache.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLCache.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 #if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
diff --git a/Tests/SkipFoundationTests/Network/TestURLComponents.swift b/Tests/SkipFoundationTests/Network/TestURLComponents.swift
index 9ee2ab7..c1465b7 100644
--- a/Tests/SkipFoundationTests/Network/TestURLComponents.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLComponents.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestURLCredential.swift b/Tests/SkipFoundationTests/Network/TestURLCredential.swift
index d287f07..bd6b201 100644
--- a/Tests/SkipFoundationTests/Network/TestURLCredential.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLCredential.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestURLCredentialStorage.swift b/Tests/SkipFoundationTests/Network/TestURLCredentialStorage.swift
index f3f0502..7cd7a61 100644
--- a/Tests/SkipFoundationTests/Network/TestURLCredentialStorage.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLCredentialStorage.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 #if !SKIP // disabled for to reduce test count and avoid io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size
diff --git a/Tests/SkipFoundationTests/Network/TestURLProtectionSpace.swift b/Tests/SkipFoundationTests/Network/TestURLProtectionSpace.swift
index 61db273..d19a5f5 100644
--- a/Tests/SkipFoundationTests/Network/TestURLProtectionSpace.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLProtectionSpace.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestURLRequest.swift b/Tests/SkipFoundationTests/Network/TestURLRequest.swift
index 48f94c9..5b5b7d9 100644
--- a/Tests/SkipFoundationTests/Network/TestURLRequest.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLRequest.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestURLResponse.swift b/Tests/SkipFoundationTests/Network/TestURLResponse.swift
index e4df07a..3187425 100644
--- a/Tests/SkipFoundationTests/Network/TestURLResponse.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLResponse.swift
@@ -1,6 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
 // These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/Network/TestURLSession.swift b/Tests/SkipFoundationTests/Network/TestURLSession.swift
index 2cf7216..288c3bc 100644
--- a/Tests/SkipFoundationTests/Network/TestURLSession.swift
+++ b/Tests/SkipFoundationTests/Network/TestURLSession.swift
@@ -1,8 +1,12 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 import XCTest
 
+#if SKIP || canImport(Darwin) // many of these tests don't build for Linux
 class TestURLSession: XCTestCase {
     func testDefaultURLSessionConfiguration() {
         let config = URLSessionConfiguration.default
@@ -10,6 +14,7 @@ class TestURLSession: XCTestCase {
         XCTAssertEqual(60.0, config.timeoutIntervalForRequest)
         XCTAssertEqual(604800.0, config.timeoutIntervalForResource)
         XCTAssertEqual(true, config.allowsCellularAccess)
+        #if !os(Linux)
         //XCTAssertEqual(true, config.allowsExpensiveNetworkAccess)
         XCTAssertEqual(true, config.allowsConstrainedNetworkAccess)
         XCTAssertEqual(false, config.waitsForConnectivity)
@@ -17,6 +22,7 @@ class TestURLSession: XCTestCase {
         XCTAssertEqual(nil, config.sharedContainerIdentifier)
         XCTAssertEqual(false, config.sessionSendsLaunchEvents)
         //XCTAssertEqual(nil, config.connectionProxyDictionary)
+        #endif
         XCTAssertEqual(false, config.httpShouldUsePipelining)
         XCTAssertEqual(true, config.httpShouldSetCookies)
         //XCTAssertEqual(nil, config.httpAdditionalHeaders)
@@ -270,6 +276,7 @@ class TestURLSession: XCTestCase {
         }
     }
 }
+#endif
 
 //
 //// These tests are adapted from https://github.com/apple/swift-corelibs-foundation/blob/main/Tests/Foundation/Tests which have the following license:
diff --git a/Tests/SkipFoundationTests/SkipFoundationTests.swift b/Tests/SkipFoundationTests/SkipFoundationTests.swift
index b0eb329..b4374ae 100644
--- a/Tests/SkipFoundationTests/SkipFoundationTests.swift
+++ b/Tests/SkipFoundationTests/SkipFoundationTests.swift
@@ -1,7 +1,9 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
+#if SKIP || canImport(OSLog)
 import OSLog
+#endif
 import XCTest
 #if !SKIP
 @testable import func SkipFoundation.SkipFoundationInternalModuleName
@@ -9,7 +11,9 @@ import XCTest
 #endif
 
 final class SkipFoundationTests: XCTestCase {
+    #if SKIP || canImport(OSLog)
     let logger: Logger = Logger(subsystem: "test", category: "SkipFoundationTests")
+    #endif
 
     func testSkipFoundation() throws {
         XCTAssertEqual(3, 1 + 2)
@@ -25,7 +29,9 @@ final class SkipFoundationTests: XCTestCase {
             if isRobolectric {
                 XCTAssertEqual(value, env[key], "Unexpected value for Robolectric system property \(key): \(env[key] ?? "")")
             } else if isAndroidEmulator {
+                #if SKIP || canImport(OSLog)
                 logger.log("ANDROID ENV: \(key)=\(env[key] ?? "")")
+                #endif
                 XCTAssertNotNil(env[key], "Android system property should not been nil for key \(key)")
             } else {
                 XCTAssertNil(env[key], "Swift system property should have been nil for key \(key) value=\(env[key] ?? "")")
diff --git a/Tests/SkipFoundationTests/System/TestNotificationCenter.swift b/Tests/SkipFoundationTests/System/TestNotificationCenter.swift
index 319e841..610cbda 100644
--- a/Tests/SkipFoundationTests/System/TestNotificationCenter.swift
+++ b/Tests/SkipFoundationTests/System/TestNotificationCenter.swift
@@ -133,6 +133,8 @@ class TestNotificationCenter : XCTestCase {
         XCTAssertTrue(flag)
     }
 
+    #if SKIP || canImport(Darwin) // i.e., not Linux
+
     func test_notificationsSequence() async {
         let notificationCenter = NotificationCenter()
         let notificationName = Notification.Name(rawValue: "test_notificationsSequence_name")
@@ -176,6 +178,8 @@ class TestNotificationCenter : XCTestCase {
         XCTAssertEqual(count, 2)
     }
 
+    #endif // SKIP || canImport(Darwin) // i.e., not Linux
+
     func test_observeOnPostingQueue() {
         #if SKIP
         throw XCTSkip("TODO")
diff --git a/Tests/SkipFoundationTests/System/TestThread.swift b/Tests/SkipFoundationTests/System/TestThread.swift
index 295f2e3..4a33f3c 100644
--- a/Tests/SkipFoundationTests/System/TestThread.swift
+++ b/Tests/SkipFoundationTests/System/TestThread.swift
@@ -26,7 +26,9 @@ class TestThread : XCTestCase {
         let thread1 = Thread.current
         let thread2 = Thread.current
         XCTAssertEqual(thread1, thread2)
+        #if !os(Linux)
         XCTAssertEqual(thread1, Thread.main)
+        #endif
     }
     
     func test_threadStart() {
@@ -69,11 +71,15 @@ class TestThread : XCTestCase {
         testInternalThreadName("Original thread")
 #else
         // No name is set initially
+        #if !os(Linux)
         XCTAssertEqual(Thread.current.name, "")
+        #endif
         testInternalThreadName("")
 #endif
         Thread.current.name = "mainThread"
+        #if !os(Linux)
         XCTAssertEqual(Thread.main.name, "mainThread")
+        #endif
         testInternalThreadName("mainThread")
 
         Thread.current.name = "12345678901234567890"
@@ -89,9 +95,13 @@ class TestThread : XCTestCase {
     }
 
     func test_mainThread() {
+        #if !os(Linux)
         XCTAssertTrue(Thread.isMainThread)
+        #endif
         let t = Thread.main
+        #if !os(Linux)
         XCTAssertTrue(t.isMainThread)
+        #endif
         let c = Thread.current
         XCTAssertTrue(c.isMainThread)
         XCTAssertTrue(c.isExecuting)
@@ -104,7 +114,9 @@ class TestThread : XCTestCase {
         let thread = Thread() {
             condition.lock()
             XCTAssertFalse(Thread.isMainThread)
+            #if !os(Linux)
             XCTAssertFalse(Thread.main == Thread.current)
+            #endif
             condition.broadcast()
             condition.unlock()
         }
diff --git a/Tests/SkipFoundationTests/XCSkipTests.swift b/Tests/SkipFoundationTests/XCSkipTests.swift
index afcac89..de3a554 100644
--- a/Tests/SkipFoundationTests/XCSkipTests.swift
+++ b/Tests/SkipFoundationTests/XCSkipTests.swift
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 import Foundation
 
-#if os(macOS)
+#if canImport(SkipTest)
 import SkipTest
 
 /// This test case will run the transpiled tests for the Skip module.