Cache is not reused every time.

[matsuji]

Scipio generates a version file for each dependency, and a cache is reused when the CacheKey of the generated file is equal.
However, sdks in a version file is a set and the order of sdks are not same every time.
As a result, the key will be changed.

The bellow version files represents the same version, but the order of sdks is not equal.

{
  "buildOptions" : {
    "enableLibraryEvolution" : true,
    "buildConfiguration" : "release",
    "isDebugSymbolsEmbedded" : true,
    "frameworkType" : "static",
    "sdks" : [
      "iOS",
      "iOSSimulator"
    ]
  },
  "targetName" : "Alamofire",
  "clangVersion" : "clang-1403.0.22.11",
  "pin" : {
    "version" : "5.6.4",
    "revision" : "78424be314842833c04bc3bef5b72e85fff99204"
  }
}

{
  "buildOptions" : {
    "enableLibraryEvolution" : true,
    "buildConfiguration" : "release",
    "isDebugSymbolsEmbedded" : true,
    "frameworkType" : "static",
    "sdks" : [
      "iOSSimulator",
      "iOS"
    ]
  },
  "targetName" : "Alamofire",
  "clangVersion" : "clang-1403.0.22.11",
  "pin" : {
    "version" : "5.6.4",
    "revision" : "78424be314842833c04bc3bef5b72e85fff99204"
  }
}

[freddi(Yuki Aki)]

sdks may not Set? @giginet

[matsuji]

Most of sdks are OrderedSet, but I found Set<SDK> here.

Scipio/Sources/ScipioKit/Runner.swift

Lines 279 to 283 in 6a50d05

 private func detectSDKsToBuild( 
     platforms: Runner.Options.PlatformSpecifier, 
     package: DescriptionPackage, 
     isSimulatorSupported: Bool 
 ) -> Set<SDK> {