Preserves JSON encoding must be explicit

nim_lk.nimble

@@ -3,6 +3,6 @@ bin = @["nim_lk"]
 description = "Tool for generating Nim lockfiles"
 license = "BSD-3-Clause"
 srcDir = "src"
-version = "20231020"
+version = "20231021"
 
-requires "nim >= 2.0.0", "preserves >= 20231020"
+requires "nim >= 2.0.0", "preserves >= 20231021"

src/nim_lk.nim

@@ -259,8 +259,12 @@ proc generateLockfile(): Preserve =
   result["depends".toPreserve] = deps
 
 proc main =
-  var lockInfo = generateLockfile()
+  var
+    stream = newFileStream(stdout)
+    lockInfo = generateLockfile()
   cannonicalize(lockInfo)
-  stdout.writeLine lockInfo
+  writeText(stream, lockInfo, textJson)
+  writeLine(stream)
+  close(stream)
 
 main()