Adds test for client -> server map propagation

* Moved the `System.getenv` side effect to the end of the world
* Adds a test to make sure that the `Map[String, String]` gets
propagated correctly
* Adds a `Ctx.Env` trait for consistency

https://github.com/lihaoyi/mill/issues/257

1 files changed, 5 insertions, 1 deletions

diff --git a/core/src/mill/util/Ctx.scala b/core/src/mill/util/Ctx.scala
index 88a8baec..6c8b2afb 100644
--- a/core/src/mill/util/Ctx.scala
+++ b/core/src/mill/util/Ctx.scala
@@ -23,6 +23,9 @@ object Ctx{
   trait Home{
     def home: Path
   }
+  trait Env{
+    def env: Map[String, String]
+  }
   object Log{
     implicit def logToCtx(l: Logger): Log = new Log { def log = l }
   }
@@ -41,7 +44,8 @@ class Ctx(val args: IndexedSeq[_],
   extends Ctx.Dest
   with Ctx.Log
   with Ctx.Args
-  with Ctx.Home{
+  with Ctx.Home
+  with Ctx.Env {
 
   def dest = dest0()
   def length = args.length