feat: support interpreter_path from py3_toolchain

py/private/entry.tmpl.sh

@@ -90,6 +90,7 @@ ln -snf "${VENV_SOURCE}/lib" "${VENV_LOCATION}/lib"
 mkdir "${VBIN_LOCATION}" 2>/dev/null || true
 ln -snf ${VENV_SOURCE}/bin/* "${VBIN_LOCATION}/"
 ln -snf "${PYTHON_LOCATION}" "${VBIN_LOCATION}/python3"
+ln -snf "${VBIN_LOCATION}/python3" "${VBIN_LOCATION}/python"
 
 echo "home = ${VBIN_LOCATION}" > "${VENV_LOCATION}/pyvenv.cfg"
 echo "include-system-site-packages = false" >> "${VENV_LOCATION}/pyvenv.cfg"

py/private/py_binary.bzl

@@ -23,12 +23,14 @@ def _py_binary_rule_imp(ctx):
         "BAZEL_TARGET_NAME": ctx.attr.name,
     }, **ctx.attr.env)
 
+    python_interpreter_path = interpreter.python.path if interpreter.uses_interpreter_path else to_manifest_path(ctx, interpreter.python)
+
     common_substitutions = {
         "{{BASH_BIN}}": bash_bin,
         "{{BASH_RLOCATION_FN}}": BASH_RLOCATION_FUNCTION,
         "{{BINARY_ENTRY_POINT}}": to_manifest_path(ctx, main),
         "{{INTERPRETER_FLAGS}}": " ".join(interpreter.flags),
-        "{{PYTHON_INTERPRETER_PATH}}": to_manifest_path(ctx, interpreter.python),
+        "{{PYTHON_INTERPRETER_PATH}}": python_interpreter_path,
         "{{RUN_BINARY_ENTRY_POINT}}": "true",
         "{{VENV_SOURCE}}": to_manifest_path(ctx, venv_info.venv_directory),
         "{{VENV_NAME}}": "%s.venv" % ctx.attr.name,

py/private/utils.bzl

@@ -15,14 +15,28 @@ def resolve_toolchain(ctx):
 
     py3_toolchain = toolchain_info.py3_runtime
 
+    interpreter = None
+    uses_interpreter_path = False
+
     if py3_toolchain.interpreter != None:
         files = depset([py3_toolchain.interpreter], transitive = [py3_toolchain.files])
+        interpreter = py3_toolchain.interpreter
     else:
         files = py3_toolchain.files
+        interpreter = struct(
+            path = py3_toolchain.interpreter_path,
+            short_path = py3_toolchain.interpreter_path,
+        )
+        files = depset([])
+        uses_interpreter_path = True
+
+    if interpreter == None:
+        fail("Unable to resolve interpreter to a path or file. Ensure `interpreter` or `interpreter_file` is defined on the py3_runtime")
 
     return struct(
         toolchain = py3_toolchain,
         files = files,
-        python = py3_toolchain.interpreter,
+        python = interpreter,
+        uses_interpreter_path = uses_interpreter_path,
         flags = ["-B", "-s", "-I"],
     )

py/private/venv/venv.bzl

@@ -125,7 +125,6 @@ def _make_venv(ctx, name = None, main = None, strip_pth_workspace_root = None):
             **{
                 "{{WHL_REQUIREMENTS_FILE}}": to_manifest_path(ctx, whl_requirements),
                 "{{PTH_FILE}}": to_manifest_path(ctx, pth),
-                "{{PYTHON_INTERPRETER_PATH}}": interpreter.python.path,
                 "{{VENV_LOCATION}}": "${BUILD_WORKSPACE_DIRECTORY}/.%s" % name,
                 "{{USE_MANIFEST_PATH}}": "true",
             }
@@ -143,7 +142,7 @@ def _make_venv(ctx, name = None, main = None, strip_pth_workspace_root = None):
         inputs = venv_creation_depset,
         command = make_venv_for_action_sh.path,
         tools = [
-            interpreter.toolchain.files,
+            interpreter.files,
         ],
         progress_message = "Creating virtual environment for %{label}",
         mnemonic = "CreateVenv",