Add python_toolchain

.bazelrc

@@ -1 +0,0 @@
-run --incompatible_use_python_toolchains=false --python_top=//:python38

BUILD

@@ -1,9 +1,30 @@
 load("@rules_python//python:defs.bzl", "py_binary")
-load("@my_deps//:requirements.bzl", "requirement")
+load("@rules_python//python:defs.bzl", "py_runtime_pair")
+load("@pip_requirements//:requirements.bzl", "requirement")
+
+py_runtime(
+    name = "python37",
+    interpreter_path = "/usr/local/bin/python3.7",
+    python_version = "PY3"
+)
 
 py_runtime(
     name = "python38",
     interpreter_path = "/usr/local/bin/python3.8",
+    python_version = "PY3"
+)
+
+py_runtime_pair(
+    name = "py_runtime_pair",
+    py3_runtime = ":python37",
+#    py3_runtime = ":python38",
+)
+
+toolchain(
+    name = "python_toolchain",
+    toolchain = ":py_runtime_pair",
+    toolchain_type = "@rules_python//python:toolchain_type",
+)
 )
 
 py_binary(

WORKSPACE

@@ -8,6 +8,8 @@ http_archive(
 
 load("@rules_python//python:pip.bzl", "pip_install")
 pip_install(
-    name = "my_deps",
+    name = "pip_requirements",
     requirements = "//:requirements.txt",
 )
+
+register_toolchains("//:python_toolchain")