Show the owner of the conflicting set in level errors

odersky · odersky · commit 2e4914d0c583 · 2025-11-01T13:53:44.000+01:00
diff --git a/compiler/src/dotty/tools/dotc/cc/CaptureSet.scala b/compiler/src/dotty/tools/dotc/cc/CaptureSet.scala
@@ -1338,7 +1338,9 @@ object CaptureSet:
             val levelStr = elem match
               case ref: TermRef => i", defined in ${ref.symbol.maybeOwner}\n"
               case _ => " "
-            i"""${elem.showAsCapability}${levelStr}cannot be included in outer capture set $cs"""
+            val ownerStr =
+              if cs.owner.exists then s" which is owned by ${cs.owner}" else ""
+            i"""${elem.showAsCapability}${levelStr}cannot be included in outer capture set $cs$ownerStr"""
           else if !elem.tryClassifyAs(cs.classifier) then
             i"""${elem.showAsCapability} is not classified as ${cs.classifier}, therefore it
                 |cannot be included in capture set $cs of ${cs.classifier.name} elements"""
diff --git a/tests/neg-custom-args/captures/boundary.check b/tests/neg-custom-args/captures/boundary.check
@@ -5,7 +5,7 @@
    |  Found:    scala.util.boundary.Label[Object^'s1]
    |  Required: scala.util.boundary.Label[Object^]^²
    |
-   |  Note that capability cap cannot be included in outer capture set 's1.
+   |  Note that capability cap cannot be included in outer capture set 's1 which is owned by val local.
    |
    |  where:    ^ and cap refer to the universal root capability
    |            ^²        refers to a fresh root capability classified as Control in the type of value local
diff --git a/tests/neg-custom-args/captures/effect-swaps-explicit.check b/tests/neg-custom-args/captures/effect-swaps-explicit.check
@@ -22,7 +22,7 @@
    |Found:    (contextual$9: boundary.Label[Result[Future[T^'s2]^'s3, E^'s4]^'s5]^'s6) ?->{fr, async} Future[T^'s7]^{fr, contextual$9}
    |Required: (boundary.Label[Result[Future[T^'s8]^'s9, E^'s10]]^) ?=> Future[T^'s8]^'s9
    |
-   |Note that capability contextual$9 cannot be included in outer capture set 's9.
+   |Note that capability contextual$9 cannot be included in outer capture set 's9 which is owned by method fail4.
    |
    |where:    ?=> refers to a fresh root capability created in method fail4 when checking argument to parameter body of method make
    |          ^   refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/effect-swaps.check b/tests/neg-custom-args/captures/effect-swaps.check
@@ -22,7 +22,7 @@
    |Found:    (contextual$9: boundary.Label[Result[Future[T^'s2]^'s3, E^'s4]^'s5]^'s6) ?->{fr, async} Future[T^'s7]^{fr, contextual$9}
    |Required: (boundary.Label[Result[Future[T^'s8]^'s9, E^'s10]]^) ?=> Future[T^'s8]^'s9
    |
-   |Note that capability contextual$9 cannot be included in outer capture set 's9.
+   |Note that capability contextual$9 cannot be included in outer capture set 's9 which is owned by method fail4.
    |
    |where:    ?=> refers to a fresh root capability created in method fail4 when checking argument to parameter body of method make
    |          ^   refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/filevar.check b/tests/neg-custom-args/captures/filevar.check
@@ -4,7 +4,7 @@
    |Found:    (l: scala.caps.Capability^) ?->'s1 File^'s2 ->'s3 Unit
    |Required: (l: scala.caps.Capability^) ?-> (f: File^{l}) => Unit
    |
-   |Note that capability l cannot be included in outer capture set 's4 of parameter f.
+   |Note that capability l cannot be included in outer capture set 's4 of parameter f which is owned by method $anonfun.
    |
    |where:    => refers to a root capability associated with the result type of (using l: scala.caps.Capability^): (f: File^{l}) => Unit
    |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/heal-tparam-cs.check b/tests/neg-custom-args/captures/heal-tparam-cs.check
@@ -4,7 +4,7 @@
    |Found:    (c: Capp^'s1) ->'s2 () ->{c} Unit
    |Required: (c: Capp^) => () ->'s3 Unit
    |
-   |Note that capability c cannot be included in outer capture set 's3.
+   |Note that capability c cannot be included in outer capture set 's3 which is owned by val test1.
    |
    |where:    => refers to a fresh root capability created in value test1 when checking argument to parameter op of method localCap
    |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/i15923.check b/tests/neg-custom-args/captures/i15923.check
@@ -4,7 +4,7 @@
    |Found:    (lcap: scala.caps.Capability^) ?->'s1 Cap^'s2 ->'s3 Id[Cap^'s4]^'s5
    |Required: (lcap: scala.caps.Capability^) ?-> Cap^{lcap} => Id[Cap^'s6]^'s7
    |
-   |Note that capability cap cannot be included in outer capture set 's6.
+   |Note that capability cap cannot be included in outer capture set 's6 which is owned by val leak.
    |
    |where:    =>  refers to a root capability associated with the result type of (using lcap: scala.caps.Capability^): Cap^{lcap} => Id[Cap^'s6]^'s7
    |          ^   refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/i15923a.check b/tests/neg-custom-args/captures/i15923a.check
@@ -4,7 +4,7 @@
   |Found:    (lcap: Cap^'s1) ->'s2 () ->'s3 Id[Cap^'s4]^'s5
   |Required: (lcap: Cap^) => () =>² Id[Cap^'s6]^'s7
   |
-  |Note that capability cap cannot be included in outer capture set 's6.
+  |Note that capability cap cannot be included in outer capture set 's6 which is owned by val leak.
   |
   |where:    =>  refers to a fresh root capability created in value leak when checking argument to parameter op of method withCap
   |          =>² refers to a root capability associated with the result type of (lcap: Cap^): () =>² Id[Cap^'s6]^'s7
diff --git a/tests/neg-custom-args/captures/i15923b.check b/tests/neg-custom-args/captures/i15923b.check
@@ -4,7 +4,7 @@
   |Found:    (x$0: Cap^) -> Id[Cap^{x$0}]
   |Required: (lcap: Cap^) => Id[Cap^'s1]^'s2
   |
-  |Note that capability lcap cannot be included in outer capture set 's1.
+  |Note that capability lcap cannot be included in outer capture set 's1 which is owned by val leak.
   |
   |where:    => refers to a fresh root capability created in value leak when checking argument to parameter op of method withCap
   |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/i21920.check b/tests/neg-custom-args/captures/i21920.check
@@ -4,7 +4,7 @@
    |Found:    (f: File^'s1) ->'s2 Cell[File^'s3]{val head: () ->'s4 IterableOnce[File^'s5]^'s6}^'s7
    |Required: File^ => Cell[File^'s8]{val head: () ->'s9 IterableOnce[File^'s10]^'s11}^'s12
    |
-   |Note that capability cap cannot be included in outer capture set 's13.
+   |Note that capability cap cannot be included in outer capture set 's13 which is owned by method $anonfun.
    |
    |where:    =>  refers to a fresh root capability created in value cell when checking argument to parameter f of method open
    |          ^   refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/lazylists-exceptions.check b/tests/neg-custom-args/captures/lazylists-exceptions.check
@@ -5,7 +5,7 @@
    |    Required: LazyList[Int]^'s1
    |
    |    Note that capability canThrow$1, defined in method try$1
-   |    cannot be included in outer capture set 's1 of method problem.
+   |    cannot be included in outer capture set 's1 of method problem which is owned by method problem.
 38 |      if i > 9 then throw Ex1()
 39 |      i * i
 40 |    }
diff --git a/tests/neg-custom-args/captures/leaking-iterators.check b/tests/neg-custom-args/captures/leaking-iterators.check
@@ -4,7 +4,7 @@
    |Found:    (log: java.io.FileOutputStream^'s1) ->'s2 cctest.Iterator[Int]^{log}
    |Required: java.io.FileOutputStream^ => cctest.Iterator[Int]^'s3
    |
-   |Note that capability log cannot be included in outer capture set 's3.
+   |Note that capability log cannot be included in outer capture set 's3 which is owned by method test.
    |
    |where:    => refers to a fresh root capability created in method test when checking argument to parameter op of method usingLogFile
    |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/real-try.check b/tests/neg-custom-args/captures/real-try.check
@@ -23,7 +23,7 @@
    |    Required: () ->'s1 Unit
    |
    |    Note that capability canThrow$2, defined in method try$2
-   |    cannot be included in outer capture set 's1 of value x.
+   |    cannot be included in outer capture set 's1 of value x which is owned by val x.
    |
    | longer explanation available when compiling with `-explain`
 -- [E007] Type Mismatch Error: tests/neg-custom-args/captures/real-try.scala:27:4 --------------------------------------
@@ -33,7 +33,7 @@
    |    Required: () ->'s3 Cell[Unit]^'s4
    |
    |    Note that capability canThrow$3, defined in method try$3
-   |    cannot be included in outer capture set 's3 of value y.
+   |    cannot be included in outer capture set 's3 of value y which is owned by val y.
    |
    | longer explanation available when compiling with `-explain`
 -- [E007] Type Mismatch Error: tests/neg-custom-args/captures/real-try.scala:33:8 --------------------------------------
@@ -43,6 +43,6 @@
    |    Required: Cell[() ->'s5 Unit]^'s6
    |
    |    Note that capability canThrow$4, defined in method try$4
-   |    cannot be included in outer capture set 's5 of value b.
+   |    cannot be included in outer capture set 's5 of value b which is owned by val b.
    |
    | longer explanation available when compiling with `-explain`
diff --git a/tests/neg-custom-args/captures/reference-cc.check b/tests/neg-custom-args/captures/reference-cc.check
@@ -4,7 +4,7 @@
    |Found:    (file: java.io.FileOutputStream^'s1) ->'s2 () ->{file} Unit
    |Required: java.io.FileOutputStream^ => () ->'s3 Unit
    |
-   |Note that capability file cannot be included in outer capture set 's3.
+   |Note that capability file cannot be included in outer capture set 's3 which is owned by val later.
    |
    |where:    => refers to a fresh root capability created in value later when checking argument to parameter op of method usingLogFile
    |          ^  refers to the universal root capability
@@ -16,7 +16,7 @@
    |Found:    (f: java.io.FileOutputStream^'s4) ->'s5 LzyList[Int]^{f}
    |Required: java.io.FileOutputStream^ => LzyList[Int]^'s6
    |
-   |Note that capability f cannot be included in outer capture set 's6.
+   |Note that capability f cannot be included in outer capture set 's6 which is owned by val xs.
    |
    |where:    => refers to a fresh root capability created in value xs when checking argument to parameter op of method usingLogFile
    |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/sep-curried-par.check b/tests/neg-custom-args/captures/sep-curried-par.check
@@ -5,7 +5,7 @@
    |                                Required: (() ->'s1 Unit) ->'s2 Unit
    |
    |                                Note that capability p1, defined in method $anonfun
-   |                                cannot be included in outer capture set 's2.
+   |                                cannot be included in outer capture set 's2 which is owned by val bar.
    |
    |                                where:    cap is the universal root capability
    |
diff --git a/tests/neg-custom-args/captures/simple-using.check b/tests/neg-custom-args/captures/simple-using.check
@@ -4,7 +4,7 @@
   |Found:    (f: java.io.FileOutputStream^'s1) ->'s2 () ->{f} Unit
   |Required: java.io.FileOutputStream^ => () ->'s3 Unit
   |
-  |Note that capability f cannot be included in outer capture set 's3.
+  |Note that capability f cannot be included in outer capture set 's3 which is owned by method test.
   |
   |where:    => refers to a fresh root capability created in method test when checking argument to parameter op of method usingLogFile
   |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/try.check b/tests/neg-custom-args/captures/try.check
@@ -37,7 +37,7 @@
    |Found:    (x: CT[Exception]^) ->'s3 () ->{x} Int
    |Required: CT[Exception]^ => () ->'s4 Int
    |
-   |Note that capability x cannot be included in outer capture set 's4.
+   |Note that capability x cannot be included in outer capture set 's4 which is owned by val xx.
    |
    |where:    => refers to a fresh root capability created in value xx when checking argument to parameter op of method handle
    |          ^  refers to the universal root capability
@@ -52,7 +52,7 @@
    |Found:    (x: CT[Exception]^) ->'s5 () ->{x} Int
    |Required: CT[Exception]^ => () ->'s6 Int
    |
-   |Note that capability x cannot be included in outer capture set 's6.
+   |Note that capability x cannot be included in outer capture set 's6 which is owned by val global.
    |
    |where:    => refers to a fresh root capability created in value global when checking argument to parameter op of method handle
    |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/usingLogFile.check b/tests/neg-custom-args/captures/usingLogFile.check
@@ -4,7 +4,7 @@
    |Found:    (f: java.io.FileOutputStream^'s1) ->'s2 () ->{f} Unit
    |Required: java.io.FileOutputStream^ => () ->'s3 Unit
    |
-   |Note that capability f cannot be included in outer capture set 's3.
+   |Note that capability f cannot be included in outer capture set 's3 which is owned by val later.
    |
    |where:    => refers to a fresh root capability created in value later when checking argument to parameter op of method usingLogFile
    |          ^  refers to the universal root capability
@@ -16,7 +16,7 @@
    |Found:    (f: java.io.FileOutputStream^'s4) ->'s5 Test2.Cell[() ->{f} Unit]^'s6
    |Required: java.io.FileOutputStream^ => Test2.Cell[() ->'s7 Unit]^'s8
    |
-   |Note that capability f cannot be included in outer capture set 's7.
+   |Note that capability f cannot be included in outer capture set 's7 which is owned by val later2.
    |
    |where:    => refers to a fresh root capability created in value later2 when checking argument to parameter op of method usingLogFile
    |          ^  refers to the universal root capability
@@ -28,7 +28,7 @@
    |Found:    (f: java.io.OutputStream^'s9) ->'s10 Int ->{f} Unit
    |Required: java.io.OutputStream^ => Int ->'s11 Unit
    |
-   |Note that capability f cannot be included in outer capture set 's11.
+   |Note that capability f cannot be included in outer capture set 's11 which is owned by val later.
    |
    |where:    => refers to a fresh root capability created in value later when checking argument to parameter op of method usingFile
    |          ^  refers to the universal root capability
@@ -40,7 +40,7 @@
    |Found:    (_$1: java.io.OutputStream^'s12) ->'s13 () ->{_$1} Unit
    |Required: java.io.OutputStream^ => () ->'s14 Unit
    |
-   |Note that capability _$1 cannot be included in outer capture set 's14.
+   |Note that capability _$1 cannot be included in outer capture set 's14 which is owned by val later.
    |
    |where:    => refers to a fresh root capability created in value later when checking argument to parameter op of method usingFile
    |          ^  refers to the universal root capability
diff --git a/tests/neg-custom-args/captures/vars.check b/tests/neg-custom-args/captures/vars.check
@@ -28,14 +28,14 @@
 -- [E007] Type Mismatch Error: tests/neg-custom-args/captures/vars.scala:36:10 -----------------------------------------
 36 |  local { cap3 => // error
    |          ^
-   |          Found:    (cap3: CC^) ->'s1 String ->{cap3} String
-   |          Required: CC^ -> String ->{cap3²} String
+   |        Found:    (cap3: CC^) ->'s1 String ->{cap3} String
+   |        Required: CC^ -> String ->{cap3²} String
    |
-   |          Note that capability cap3 cannot be included in outer capture set {cap3²}.
+   |        Note that capability cap3 cannot be included in outer capture set {cap3²} which is owned by method test.
    |
-   |          where:    ^     refers to the universal root capability
-   |                    cap3  is a reference to a value parameter
-   |                    cap3² is a parameter in an anonymous function in method test
+   |        where:    ^     refers to the universal root capability
+   |                  cap3  is a reference to a value parameter
+   |                  cap3² is a parameter in an anonymous function in method test
 37 |    def g(x: String): String = if cap3 == cap3 then "" else "a"
 38 |    g
    |

Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@`
`5`	`5`	`\| Found: scala.util.boundary.Label[Object^'s1]`
`6`	`6`	`\| Required: scala.util.boundary.Label[Object^]^²`
`7`	`7`	`\|`
`8`		`- \| Note that capability cap cannot be included in outer capture set 's1.`
	`8`	`+ \| Note that capability cap cannot be included in outer capture set 's1 which is owned by val local.`
`9`	`9`	`\|`
`10`	`10`	`\| where: ^ and cap refer to the universal root capability`
`11`	`11`	`\| ^² refers to a fresh root capability classified as Control in the type of value local`
Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,7 @@`
`22`	`22`	`\|Found: (contextual$9: boundary.Label[Result[Future[T^'s2]^'s3, E^'s4]^'s5]^'s6) ?->{fr, async} Future[T^'s7]^{fr, contextual$9}`
`23`	`23`	`\|Required: (boundary.Label[Result[Future[T^'s8]^'s9, E^'s10]]^) ?=> Future[T^'s8]^'s9`
`24`	`24`	`\|`
`25`		`- \|Note that capability contextual$9 cannot be included in outer capture set 's9.`
	`25`	`+ \|Note that capability contextual$9 cannot be included in outer capture set 's9 which is owned by method fail4.`
`26`	`26`	`\|`
`27`	`27`	`\|where: ?=> refers to a fresh root capability created in method fail4 when checking argument to parameter body of method make`
`28`	`28`	`\| ^ refers to the universal root capability`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`\|Found: (l: scala.caps.Capability^) ?->'s1 File^'s2 ->'s3 Unit`
`5`	`5`	`\|Required: (l: scala.caps.Capability^) ?-> (f: File^{l}) => Unit`
`6`	`6`	`\|`
`7`		`- \|Note that capability l cannot be included in outer capture set 's4 of parameter f.`
	`7`	`+ \|Note that capability l cannot be included in outer capture set 's4 of parameter f which is owned by method $anonfun.`
`8`	`8`	`\|`
`9`	`9`	`\|where: => refers to a root capability associated with the result type of (using l: scala.caps.Capability^): (f: File^{l}) => Unit`
`10`	`10`	`\| ^ refers to the universal root capability`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`\|Found: (c: Capp^'s1) ->'s2 () ->{c} Unit`
`5`	`5`	`\|Required: (c: Capp^) => () ->'s3 Unit`
`6`	`6`	`\|`
`7`		`- \|Note that capability c cannot be included in outer capture set 's3.`
	`7`	`+ \|Note that capability c cannot be included in outer capture set 's3 which is owned by val test1.`
`8`	`8`	`\|`
`9`	`9`	`\|where: => refers to a fresh root capability created in value test1 when checking argument to parameter op of method localCap`
`10`	`10`	`\| ^ refers to the universal root capability`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`\|Found: (lcap: scala.caps.Capability^) ?->'s1 Cap^'s2 ->'s3 Id[Cap^'s4]^'s5`
`5`	`5`	`\|Required: (lcap: scala.caps.Capability^) ?-> Cap^{lcap} => Id[Cap^'s6]^'s7`
`6`	`6`	`\|`
`7`		`- \|Note that capability cap cannot be included in outer capture set 's6.`
	`7`	`+ \|Note that capability cap cannot be included in outer capture set 's6 which is owned by val leak.`
`8`	`8`	`\|`
`9`	`9`	`\|where: => refers to a root capability associated with the result type of (using lcap: scala.caps.Capability^): Cap^{lcap} => Id[Cap^'s6]^'s7`
`10`	`10`	`\| ^ refers to the universal root capability`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`\|Found: (lcap: Cap^'s1) ->'s2 () ->'s3 Id[Cap^'s4]^'s5`
`5`	`5`	`\|Required: (lcap: Cap^) => () =>² Id[Cap^'s6]^'s7`
`6`	`6`	`\|`
`7`		`- \|Note that capability cap cannot be included in outer capture set 's6.`
	`7`	`+ \|Note that capability cap cannot be included in outer capture set 's6 which is owned by val leak.`
`8`	`8`	`\|`
`9`	`9`	`\|where: => refers to a fresh root capability created in value leak when checking argument to parameter op of method withCap`
`10`	`10`	`\| =>² refers to a root capability associated with the result type of (lcap: Cap^): () =>² Id[Cap^'s6]^'s7`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`\|Found: (x$0: Cap^) -> Id[Cap^{x$0}]`
`5`	`5`	`\|Required: (lcap: Cap^) => Id[Cap^'s1]^'s2`
`6`	`6`	`\|`
`7`		`- \|Note that capability lcap cannot be included in outer capture set 's1.`
	`7`	`+ \|Note that capability lcap cannot be included in outer capture set 's1 which is owned by val leak.`
`8`	`8`	`\|`
`9`	`9`	`\|where: => refers to a fresh root capability created in value leak when checking argument to parameter op of method withCap`
`10`	`10`	`\| ^ refers to the universal root capability`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`\|Found: (f: File^'s1) ->'s2 Cell[File^'s3]{val head: () ->'s4 IterableOnce[File^'s5]^'s6}^'s7`
`5`	`5`	`\|Required: File^ => Cell[File^'s8]{val head: () ->'s9 IterableOnce[File^'s10]^'s11}^'s12`
`6`	`6`	`\|`
`7`		`- \|Note that capability cap cannot be included in outer capture set 's13.`
	`7`	`+ \|Note that capability cap cannot be included in outer capture set 's13 which is owned by method $anonfun.`
`8`	`8`	`\|`
`9`	`9`	`\|where: => refers to a fresh root capability created in value cell when checking argument to parameter f of method open`
`10`	`10`	`\| ^ refers to the universal root capability`