Fix path error disgnastics

Fix wording so that it works for nested errors as well.
Incorparte Tiark's latest example.

2 files changed, 6 insertions, 7 deletions

diff --git a/src/dotty/tools/dotc/core/TypeOps.scala b/src/dotty/tools/dotc/core/TypeOps.scala
index 9fcc6abbc..882ab9f10 100644
--- a/src/dotty/tools/dotc/core/TypeOps.scala
+++ b/src/dotty/tools/dotc/core/TypeOps.scala
@@ -674,7 +674,6 @@ trait TypeOps { this: Context => // TODO: Make standalone object.
     if (scala2Mode) migrationWarning(msg, pos)
     scala2Mode
   }
-
 }
 
 object TypeOps {
@@ -687,16 +686,16 @@ object TypeOps {
 
   object Realizable extends Realizability("")
 
-  object NotConcrete extends Realizability("it is not a concrete type")
+  object NotConcrete extends Realizability(" is not a concrete type")
 
-  object NotStable extends Realizability("it is not a stable reference")
+  object NotStable extends Realizability(" is not a stable reference")
 
   class NotFinal(sym: Symbol)(implicit ctx: Context)
-  extends Realizability(i"it refers to nonfinal $sym")
+  extends Realizability(i" refers to nonfinal $sym")
 
   class HasProblemBounds(mbr: SingleDenotation)(implicit ctx: Context)
-  extends Realizability(i"it has a member $mbr with possibly conflicting bounds ${mbr.info.bounds.lo} <: ... <: ${mbr.info.bounds.hi}")
+  extends Realizability(i" has a member $mbr with possibly conflicting bounds ${mbr.info.bounds.lo} <: ... <: ${mbr.info.bounds.hi}")
 
   class ProblemInUnderlying(tp: Type, problem: Realizability)(implicit ctx: Context)
-  extends Realizability(i"its underlying type ${tp} ${problem.msg}")
+  extends Realizability(i"s underlying type ${tp}${problem.msg}")
 }
diff --git a/src/dotty/tools/dotc/typer/Checking.scala b/src/dotty/tools/dotc/typer/Checking.scala
index ee1c2a061..ca7c5c5ab 100644
--- a/src/dotty/tools/dotc/typer/Checking.scala
+++ b/src/dotty/tools/dotc/typer/Checking.scala
@@ -325,7 +325,7 @@ trait Checking {
   def checkRealizable(tp: Type, pos: Position)(implicit ctx: Context): Unit = {
     val rstatus = ctx.realizability(tp)
     if (rstatus ne TypeOps.Realizable) {
-      def msg = d"$tp is not a legal path since ${rstatus.msg}"
+      def msg = d"$tp is not a legal path since it${rstatus.msg}"
       if (ctx.scala2Mode) ctx.migrationWarning(msg, pos) else ctx.error(msg, pos)
     }
   }