Exception.getMessage can be null

cache/src/main/scala/coursier/Cache.scala

@@ -204,7 +204,7 @@ object Cache {
         -\/(FileError.ConcurrentDownload(url))
     }
     catch { case e: Exception =>
-      -\/(FileError.DownloadError(s"Caught $e (${e.getMessage})"))
+      -\/(FileError.DownloadError(s"Caught $e${Option(e.getMessage).fold("")(" (" + _ + ")")}"))
     }
 
   private def temporaryFile(file: File): File = {
@@ -232,7 +232,7 @@ object Cache {
 
         def printError(e: Exception): Unit =
           scala.Console.err.println(
-            s"Cannot instantiate $clsName: $e${Option(e.getMessage).map(" ("+_+")")}"
+            s"Cannot instantiate $clsName: $e${Option(e.getMessage).fold("")(" ("+_+")")}"
           )
 
         val handlerOpt = clsOpt.flatMap {
@@ -811,18 +811,6 @@ object Cache {
     buffer.toByteArray
   }
 
-  def readFully(is: => InputStream) =
-    Task {
-      \/.fromTryCatchNonFatal {
-        val is0 = is
-        val b =
-          try readFullySync(is0)
-          finally is0.close()
-
-        new String(b, "UTF-8")
-      } .leftMap(_.getMessage)
-    }
-
   def withContent(is: InputStream, f: (Array[Byte], Int) => Unit): Unit = {
     val data = Array.ofDim[Byte](16384)
 

cache/src/main/scala/coursier/CacheParse.scala

@@ -31,7 +31,7 @@ object CacheParse {
         repo.success
       } catch {
         case e: MalformedURLException =>
-          ("Error parsing URL " + url + Option(e.getMessage).map(" (" + _ + ")").mkString).failure
+          ("Error parsing URL " + url + Option(e.getMessage).fold("")(" (" + _ + ")")).failure
       }
     }
 

cache/src/main/scala/coursier/Platform.scala

@@ -32,10 +32,10 @@ object Platform {
 
         new String(b, "UTF-8")
       } .leftMap{
-        case e: java.io.FileNotFoundException =>
+        case e: java.io.FileNotFoundException if e.getMessage != null =>
           s"Not found: ${e.getMessage}"
         case e =>
-          s"$e: ${e.getMessage}"
+          s"$e${Option(e.getMessage).fold("")(" (" + _ + ")")}"
       }
     }
 

cli/src/main/scala-2.11/coursier/cli/Bootstrap.scala

@@ -193,7 +193,7 @@ case class Bootstrap(
 
   try Files.write(output0.toPath, shellPreamble.getBytes("UTF-8") ++ buffer.toByteArray)
   catch { case e: IOException =>
-    Console.err.println(s"Error while writing $output0: ${e.getMessage}")
+    Console.err.println(s"Error while writing $output0${Option(e.getMessage).fold("")(" (" + _ + ")")}")
     sys.exit(1)
   }
 
@@ -218,7 +218,10 @@ case class Bootstrap(
     case e: UnsupportedOperationException =>
       // Ignored
     case e: IOException =>
-      Console.err.println(s"Error while making $output0 executable: ${e.getMessage}")
+      Console.err.println(
+        s"Error while making $output0 executable" +
+          Option(e.getMessage).fold("")(" (" + _ + ")")
+      )
       sys.exit(1)
   }
 

core/jvm/src/main/scala/coursier/core/compatibility/package.scala

@@ -14,7 +14,7 @@ package object compatibility {
   def xmlParse(s: String): Either[String, Xml.Node] = {
     def parse =
       try Right(scala.xml.XML.loadString(s))
-      catch { case e: Exception => Left(e.getMessage) }
+      catch { case e: Exception => Left(e.toString + Option(e.getMessage).fold("")(" (" + _ + ")")) }
 
     def fromNode(node: scala.xml.Node): Xml.Node =
       new Xml.Node {

fetch-js/src/main/scala/coursier/Platform.scala

@@ -80,7 +80,7 @@ object Platform {
         get(artifact.url)
           .map(\/-(_))
           .recover { case e: Exception =>
-          -\/(e.getMessage)
+          -\/(e.toString + Option(e.getMessage).fold("")(" (" + _ + ")"))
         }
       }
     )
@@ -104,9 +104,10 @@ object Platform {
           .flatMap(_ => get(artifact.url))
           .map { s => logger.fetched(artifact.url); \/-(s) }
           .recover { case e: Exception =>
-          logger.other(artifact.url, e.getMessage)
-          -\/(e.getMessage)
-        }
+            val msg = e.toString + Option(e.getMessage).fold("")(" (" + _ + ")")
+            logger.other(artifact.url, msg)
+            -\/(msg)
+          }
       }
     )
   }

plugin/src/main/scala-2.10/coursier/FromSbt.scala

@@ -155,7 +155,7 @@ object FromSbt {
         log.warn(
           "Error parsing Maven repository base " +
           root +
-          Option(e.getMessage).map(" (" + _ + ")").mkString +
+          Option(e.getMessage).fold("")(" (" + _ + ")") +
           ", ignoring it"
         )