go: fixed GOROOT_BOOTSTRAP without workarounds (#2671)

var/spack/repos/builtin/packages/go-bootstrap/package.py

@@ -87,5 +87,8 @@ def install(self, spec, prefix):
             else:
                 shutil.copy2(f, os.path.join(prefix, f))
 
+    def setup_dependent_environment(self, spack_env, run_env, dep_spec):
+        spack_env.set('GOROOT_BOOTSTRAP', self.spec.prefix)
+
     def setup_environment(self, spack_env, run_env):
         spack_env.set('GOROOT_FINAL', self.spec.prefix)

var/spack/repos/builtin/packages/go/package.py

@@ -47,7 +47,7 @@
 class Go(Package):
     """The golang compiler and build environment"""
     homepage = "https://golang.org"
-    url='https://storage.googleapis.com/golang/go1.7.4.src.tar.gz'
+    url = 'https://storage.googleapis.com/golang/go1.7.4.src.tar.gz'
 
     extendable = True
 
@@ -104,14 +104,7 @@ def install(self, spec, prefix):
                 shutil.copy2(f, os.path.join(prefix, f))
 
     def setup_environment(self, spack_env, run_env):
-        try:
-            spack_env.set('GOROOT_FINAL', self.spec.prefix)
-            spack_env.set('GOROOT_BOOTSTRAP', self.spec['go-bootstrap'].prefix)
-        except KeyError:
-            # Needed because we try to get a build-only
-            # dependency, and this may fail during module 
-            # file creation
-            pass
+        spack_env.set('GOROOT_FINAL', self.spec.prefix)
 
     def setup_dependent_package(self, module, ext_spec):
         """Called before go modules' install() methods.