Give VCR its own "msgSnapshotNotFound" message.

Author: nedtwigg

jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/Mode.kt

@@ -47,6 +47,7 @@ enum class Mode {
       msg("Snapshot " + SnapshotNotEqualErrorMsg.forUnequalStrings(expected, actual))
   internal fun msgSnapshotMismatchBinary(expected: ByteArray, actual: ByteArray) =
       msgSnapshotMismatch(expected.toQuotedPrintable(), actual.toQuotedPrintable())
+  internal fun msgVcrSnapshotNotFound() = msg("VCR snapshot not found")
   internal fun msgVcrMismatch(key: String, expected: String, actual: String) =
       msg("VCR frame $key " + SnapshotNotEqualErrorMsg.forUnequalStrings(expected, actual))
   internal fun msgVcrUnread(expected: Int, actual: Int) =

jvm/selfie-lib/src/commonMain/kotlin/com/diffplug/selfie/VcrSelfie.kt

@@ -45,7 +45,7 @@ internal constructor(
     if (state.readMode) {
       val snapshot =
           disk.readDisk(sub, call)
-              ?: throw Selfie.system.fs.assertFailed(Selfie.system.mode.msgSnapshotNotFound())
+              ?: throw Selfie.system.fs.assertFailed(Selfie.system.mode.msgVcrSnapshotNotFound())
       var idx = 1
       for ((key, value) in snapshot.facets) {
         check(key.startsWith(OPEN))