message: SWIFTC might not always be set, fallback in the same way the Makefile does.
diff: @@ -14,6 +14,7 @@ from lldbsuite.test.decorators import *
  import lldbsuite.test.lldbtest as lldbtest
  import lldbsuite.test.lldbutil as lldbutil
  import os
  +import swift
  import unittest2
  @@ -25,7 +26,11 @@ class TestSwiftBackwardsCompatibilitySimple(lldbtest.TestBase):
  @skipIf(compiler="swiftc", compiler_version=['<', '5.0'])
  @add_test_categories(["swiftpr", "swift-history"])
  def test_simple(self):
  - version = self.getCompilerVersion(os.environ['SWIFTC'])
  + if 'SWIFTC' in os.environ:
  + compiler = os.environ['SWIFTC']
  + else:
  + compiler = swift.getSwiftCompiler()
  + version = self.getCompilerVersion(compiler)
  if version < '5.0':
  self.skipTest('Swift compiler predates stable ABI')
  self.build()
  