Add Linux support for SwiftMETAR core library and DecodeWindsAloft

.github/workflows/ci.yml

@@ -3,7 +3,10 @@
 # Category A (tools-version 6.2 + macOS 26 min): macos-26 + Swift 6.2
 # Category B (tools-version 6.2 + older macOS):  macos-15 + 6.2, macos-26 + 6.2
 # Category C (tools-version 6.0):                macos-15 + 6.1, macos-15 + 6.3, macos-26 + 6.3
-# Linux (if viable):                             ubuntu + Swift 6.1, ubuntu + Swift 6.3
+# Linux:                                          ubuntu + Swift 6.1, ubuntu + Swift 6.3
+#   (Package.swift excludes METARFormatting/DecodeMETAR/DecodeTAF on Linux — they format
+#   Measurement values via APIs swift-corelibs-foundation doesn't implement; SwiftMETAR
+#   core + DecodeWindsAloft + tests are unaffected and build/test on Linux normally)
 #
 # When Swift 6.4 ships: bump 6.1→6.2 and 6.3→6.4 in Category C
 # When bumping tools-version to 6.2: drop 6.0/6.1, move to Category A or B
@@ -33,6 +36,10 @@ jobs:
             swift: "6.3"
           - os: macos-26
             swift: "6.3"
+          - os: ubuntu-latest
+            swift: "6.1"
+          - os: ubuntu-latest
+            swift: "6.3"
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v6
@@ -45,11 +52,10 @@ jobs:
         run: swift test -v
   lint:
     name: Run SwiftLint
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
+    container: ghcr.io/realm/swiftlint:latest
     steps:
       - uses: actions/checkout@v6
-      - name: Install SwiftLint
-        run: brew install swiftlint
       - name: Run SwiftLint
         run: swiftlint --strict
   swift-format:

Package.swift

@@ -7,40 +7,55 @@ let approachableConcurrency: [SwiftSetting] = [
   .enableUpcomingFeature("InferIsolatedConformances")
 ]
 
-let package = Package(
-  name: "SwiftMETAR",
-  defaultLocalization: "en",
-  platforms: [.macOS(.v13), .iOS(.v16), .tvOS(.v16), .watchOS(.v9), .visionOS(.v1)],
-  products: [
-    // Products define the executables and libraries a package produces, and make them visible to other packages.
-    .library(
-      name: "SwiftMETAR",
-      targets: ["SwiftMETAR"]
-    ),
+// METARFormatting (and DecodeMETAR/DecodeTAF, which depend on it) format `Measurement`
+// values using `Measurement.FormatStyle` and the `\(_, format:)` string interpolation
+// sugar for custom `FormatStyle` types. Neither is implemented by swift-corelibs-foundation,
+// so these targets/products are only defined on Apple platforms; SwiftMETAR and
+// DecodeWindsAloft don't use these APIs and build fine everywhere.
+var products: [Product] = [
+  // Products define the executables and libraries a package produces, and make them visible to other packages.
+  .library(
+    name: "SwiftMETAR",
+    targets: ["SwiftMETAR"]
+  ),
+  .executable(name: "decode-winds-aloft", targets: ["DecodeWindsAloft"])
+]
+
+var targets: [Target] = [
+  // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+  // Targets can depend on other targets in this package, and on products in packages this package depends on.
+  .target(
+    name: "SwiftMETAR",
+    dependencies: [.product(name: "NumberKit", package: "swift-numberkit")],
+    resources: [.process("Resources")],
+    swiftSettings: approachableConcurrency
+  ),
+  .testTarget(
+    name: "SwiftMETARTests",
+    dependencies: ["SwiftMETAR"],
+    swiftSettings: approachableConcurrency
+  ),
+  .executableTarget(
+    name: "DecodeWindsAloft",
+    dependencies: [
+      "SwiftMETAR",
+      .product(name: "ArgumentParser", package: "swift-argument-parser")
+    ],
+    swiftSettings: approachableConcurrency
+  )
+]
+
+#if !os(Linux)
+  products += [
     .library(
       name: "METARFormatting",
       targets: ["METARFormatting"]
     ),
     .executable(name: "decode-metar", targets: ["DecodeMETAR"]),
-    .executable(name: "decode-taf", targets: ["DecodeTAF"]),
-    .executable(name: "decode-winds-aloft", targets: ["DecodeWindsAloft"])
-  ],
-  dependencies: [
-    // Dependencies declare other packages that this package depends on.
-    .package(url: "https://github.com/objecthub/swift-numberkit.git", from: "2.6.0"),
-    .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.4.3"),
-    .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.5.0"),
-    .package(url: "https://github.com/riscfuture/BuildableMacro.git", from: "1.0.0")
-  ],
-  targets: [
-    // Targets are the basic building blocks of a package. A target can define a module or a test suite.
-    // Targets can depend on other targets in this package, and on products in packages this package depends on.
-    .target(
-      name: "SwiftMETAR",
-      dependencies: [.product(name: "NumberKit", package: "swift-numberkit")],
-      resources: [.process("Resources")],
-      swiftSettings: approachableConcurrency
-    ),
+    .executable(name: "decode-taf", targets: ["DecodeTAF"])
+  ]
+
+  targets += [
     .target(
       name: "METARFormatting",
       dependencies: [
@@ -50,11 +65,6 @@ let package = Package(
       resources: [.process("Resources")],
       swiftSettings: approachableConcurrency
     ),
-    .testTarget(
-      name: "SwiftMETARTests",
-      dependencies: ["SwiftMETAR"],
-      swiftSettings: approachableConcurrency
-    ),
     .executableTarget(
       name: "DecodeMETAR",
       dependencies: [
@@ -72,15 +82,22 @@ let package = Package(
         .product(name: "ArgumentParser", package: "swift-argument-parser")
       ],
       swiftSettings: approachableConcurrency
-    ),
-    .executableTarget(
-      name: "DecodeWindsAloft",
-      dependencies: [
-        "SwiftMETAR",
-        .product(name: "ArgumentParser", package: "swift-argument-parser")
-      ],
-      swiftSettings: approachableConcurrency
     )
+  ]
+#endif
+
+let package = Package(
+  name: "SwiftMETAR",
+  defaultLocalization: "en",
+  platforms: [.macOS(.v13), .iOS(.v16), .tvOS(.v16), .watchOS(.v9), .visionOS(.v1)],
+  products: products,
+  dependencies: [
+    // Dependencies declare other packages that this package depends on.
+    .package(url: "https://github.com/objecthub/swift-numberkit.git", from: "2.6.0"),
+    .package(url: "https://github.com/apple/swift-docc-plugin.git", from: "1.4.3"),
+    .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.5.0"),
+    .package(url: "https://github.com/riscfuture/BuildableMacro.git", from: "1.0.0")
   ],
+  targets: targets,
   swiftLanguageModes: [.v5, .v6]
 )

Sources/DecodeMETAR/DecodeMETAR.swift

@@ -1,5 +1,8 @@
 import ArgumentParser
 import Foundation
+#if canImport(FoundationNetworking)
+  import FoundationNetworking
+#endif
 import METARFormatting
 import SwiftMETAR
 

Sources/DecodeTAF/DecodeTAF.swift

@@ -1,5 +1,8 @@
 import ArgumentParser
 import Foundation
+#if canImport(FoundationNetworking)
+  import FoundationNetworking
+#endif
 import METARFormatting
 import SwiftMETAR
 

Sources/DecodeWindsAloft/DecodeWindsAloft.swift

@@ -1,5 +1,8 @@
 import ArgumentParser
 import Foundation
+#if canImport(FoundationNetworking)
+  import FoundationNetworking
+#endif
 import SwiftMETAR
 
 @available(macOS 15.0, *)