typing only needed for python 3.5 and previous (#1778)

Author: bottler

packaging/conda/build_vision.sh

@@ -157,6 +157,12 @@ for py_ver in "${DESIRED_PYTHON[@]}"; do
     rm -rf "$output_folder"
     mkdir "$output_folder"
 
+    if [[ "$py_ver" == 3.5 ]]; then
+	export CONDA_TYPING_CONSTRAINT="- typing"
+    else
+	export CONDA_TYPING_CONSTRAINT=""
+    fi
+
     export VSTOOLCHAIN_PACKAGE=vs2017
 
     # We need to build the compiler activation scripts first on Windows

packaging/pkg_helpers.bash

@@ -115,13 +115,23 @@ setup_macos() {
   fi
 }
 
+# set variable to determine whether the typing library needs to be built in
+setup_typing() {
+  if [[ "$PYTHON_VERSION" == 3.5 ]]; then
+    export CONDA_TYPING_CONSTRAINT="- typing"
+  else
+    export CONDA_TYPING_CONSTRAINT=""
+  fi
+}
+
 # Top-level entry point for things every package will need to do
 #
 # Usage: setup_env 0.2.0
 setup_env() {
   setup_cuda
   setup_build_version "$1"
   setup_macos
+  setup_typing
 }
 
 # Function to retry functions that sometimes timeout or have flaky failures

packaging/torchvision/meta.yaml

@@ -47,7 +47,7 @@ test:
     - mock
     - av
     - ca-certificates
-    - typing
+    {{ environ.get('CONDA_TYPING_CONSTRAINT') }}
   commands:
     pytest .