Exit immediately when linting with a version other than swift_version if defined (#2491)

CHANGELOG.md

@@ -39,6 +39,11 @@
   [Timofey Solonin](https://github.com/biboran)
   [#2435](https://github.com/realm/SwiftLint/issues/2435)
 
+* The `lint` command now exits with a code of 2 when not using pinned
+  version defined as `swiftlint_version` in the configuration file.  
+  [Timofey Solonin](https://github.com/kimdv)
+  [#2074](https://github.com/realm/SwiftLint/issues/2074)
+
 #### Bug Fixes
 
 * Fix false positive in `nimble_operator` rule.  

Source/SwiftLintFramework/Models/Configuration.swift

@@ -58,6 +58,7 @@ public struct Configuration: Hashable {
         if let pinnedVersion = swiftlintVersion, pinnedVersion != Version.current.value {
             queuedPrintError("Currently running SwiftLint \(Version.current.value) but " +
                 "configuration specified version \(pinnedVersion).")
+            exit(2)
         }
 
         let configuredRules = configuredRules