added custom platform

third_party/toolchains/BUILD

@@ -73,3 +73,23 @@ platform(
         }
         """,
 )
+
+# This target is auto-generated from release/cpp.tpl and should not be
+# modified directly.
+toolchain(
+    name = "cc-toolchain-clang-x86_64-default",
+    exec_compatible_with = [
+        "@bazel_tools//platforms:linux",
+        "@bazel_tools//platforms:x86_64",
+        "@bazel_tools//tools/cpp:clang",
+        "//constraints:xenial",
+    ],
+    target_compatible_with = [
+        "//third_party/toolchains:rbe_ubuntu1604",
+        "//third_party/toolchains:rbe_ubuntu1604_large",
+        "@bazel_tools//platforms:linux",
+        "@bazel_tools//platforms:x86_64",
+    ],
+    toolchain = "//configs/ubuntu16_04_clang/1.1/bazel_0.16.1/default:cc-compiler-k8",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)

tools/remote_build/rbe_common.bazelrc

@@ -19,7 +19,7 @@
 startup --host_jvm_args=-Dbazel.DigestFunction=SHA256
 
 build --crosstool_top=@bazel_toolchains//configs/ubuntu16_04_clang/1.1/bazel_0.16.1/default:toolchain
-build --extra_toolchains=@bazel_toolchains//configs/ubuntu16_04_clang/1.1/bazel_0.16.1/cpp:cc-toolchain-clang-x86_64-default
+build --extra_toolchains=//third_party/toolchains:cc-toolchain-clang-x86_64-default
 # Use custom execution platforms defined in third_party/toolchains
 build --extra_execution_platforms=//third_party/toolchains:rbe_ubuntu1604,//third_party/toolchains:rbe_ubuntu1604_large
 build --host_platform=//third_party/toolchains:rbe_ubuntu1604