Ensure DART_CONFIGURATION is exported and don't run code in checked mode.

pkg/front_end/tool/fasta

 #!/bin/bash
 # Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 set -e
 
 REPO_DIR="$(git rev-parse --show-toplevel)"
 
-# TODO(ahe): We currently rely on the Dart VM wrapper script to define
-# DART_CONFIGURATION for locating platform.dill.
 DART_VM="${REPO_DIR}/sdk/bin/dart"
 
 TOOL_DIR="${REPO_DIR}/pkg/front_end/tool/_fasta"
 
 KERNEL_BIN="${REPO_DIR}/pkg/kernel/bin"
 
 function stop {
   echo "$@" >&2
   exit 1
 }
 
-DART_CONFIGURATION=${DART_CONFIGURATION:-ReleaseX64}
+export DART_CONFIGURATION=${DART_CONFIGURATION:-ReleaseX64}
 
 case "${1//_/-}" in
   abcompile) SCRIPT="${TOOL_DIR}/abcompile.dart";;
   analyzer-compile) SCRIPT="${TOOL_DIR}/analyzer_compile.dart";;
   compile) SCRIPT="${TOOL_DIR}/compile.dart";;
   compile-platform) SCRIPT="${TOOL_DIR}/compile_platform.dart";;
   compile-platform-dartk)
     SCRIPT="${TOOL_DIR}/compile_platform_dartk.dart"
     if [ "$#" != "2" ]; then
       stop "Usage: $1 file"
@@ skipping 13 matching lines @@
     fi
     if [ "$#" != "3" ]; then
       stop "Usage: $1 dillfile [output]"
     fi
     ;;
   kernel-service)
     shift
     PATCHED_SDK_DIR=$(
       ls -d {xcodebuild,out}/${DART_CONFIGURATION}/patched_sdk 2>/dev/null \
         | head -1)
-    exec "${DART_VM}" -c -DDFE_VERBOSE=true \
+    exec "${DART_VM}" -DDFE_VERBOSE=true \
          --platform=${PATCHED_SDK_DIR}/platform.dill \
          --dfe="${REPO_DIR}/utils/kernel-service/kernel-service.dart" "$@"
     ;;
   testing)
     SCRIPT="${REPO_DIR}/pkg/testing/bin/testing.dart"
     set -- "$@" "--config=${REPO_DIR}/pkg/front_end/test/fasta/testing.json"
     ;;
   generate-messages) SCRIPT="${TOOL_DIR}/generate_messages.dart";;
   *)
     stop "'$1' isn't a valid subcommand."
     ;;
 esac
 
 shift
 
 exec "${DART_VM}" -c "${SCRIPT}" "$@"