Bazel: Add python3 target.

WORKSPACE.in

@@ -269,12 +269,6 @@ new_local_repository(
     path = "/usr",
 )
 
-new_local_repository(
-    name = "python3",
-    build_file = "third_party/python3.BUILD",
-    path = "/usr",
-)
-
 # PyTorch
 new_local_repository(
     name = "pytorch",

cyber/py_wrapper/BUILD

@@ -37,7 +37,7 @@ cc_library(
     defines = ["PY_MAJOR_VERSION=3"],
     deps = [
         "//cyber:cyber_core",
-        "@python3",
+        "//third_party:python3",
     ],
 )
 
@@ -86,7 +86,7 @@ cc_library(
     deps = [
         "//cyber/message:py_message",
         "//cyber/record",
-        "@python3",
+        "//third_party:python3",
     ],
 )
 
@@ -136,8 +136,8 @@ cc_library(
     defines = ["PY_MAJOR_VERSION=3"],
     deps = [
         "//cyber:cyber_core",
+        "//third_party:python3",
         "@fastrtps",
-        "@python3",
     ],
 )
 
@@ -174,7 +174,7 @@ cc_library(
     defines = ["PY_MAJOR_VERSION=3"],
     deps = [
         "//cyber:cyber_core",
-        "@python3",
+        "//third_party:python3",
     ],
 )
 
@@ -213,7 +213,7 @@ cc_library(
     deps = [
         ":py3_cyber",
         "//cyber:cyber_core",
-        "@python3",
+        "//third_party:python3",
     ],
 )
 

third_party/BUILD

@@ -1,13 +1,10 @@
 package(default_visibility = ["//visibility:public"])
 
-cc_library(
-    name = "uuid",
-    linkopts = ["-luuid"],
-)
+# Libs provided by the system.
 
 cc_library(
-    name = "rt",
-    linkopts = ["-lrt"],
+    name = "ncurses",
+    linkopts = ["-lncurses"],
 )
 
 cc_library(
@@ -16,6 +13,16 @@ cc_library(
 )
 
 cc_library(
-    name = "ncurses",
-    linkopts = ["-lncurses"],
+    name = "python3",
+    linkopts = ["-lpython3.6m"],
+)
+
+cc_library(
+    name = "rt",
+    linkopts = ["-lrt"],
+)
+
+cc_library(
+    name = "uuid",
+    linkopts = ["-luuid"],
 )