comment: use exec toolchain

Author: aignas

python/uv/private/lock.bzl

@@ -20,7 +20,7 @@ load("@pythons_hub//:versions.bzl", "DEFAULT_PYTHON_VERSION", "MINOR_MAPPING")
 load("//python:py_binary.bzl", "py_binary")
 load("//python/private:bzlmod_enabled.bzl", "BZLMOD_ENABLED")  # buildifier: disable=bzl-visibility
 load("//python/private:full_version.bzl", "full_version")
-load("//python/private:toolchain_types.bzl", "TARGET_TOOLCHAIN_TYPE")  # buildifier: disable=bzl-visibility
+load("//python/private:toolchain_types.bzl", "EXEC_TOOLS_TOOLCHAIN_TYPE")  # buildifier: disable=bzl-visibility
 load(":toolchain_types.bzl", "UV_TOOLCHAIN_TYPE")
 
 visibility(["//..."])
@@ -83,7 +83,7 @@ def _lock_impl(ctx):
     toolchain_info = ctx.toolchains[UV_TOOLCHAIN_TYPE]
     uv = toolchain_info.uv_toolchain_info.uv[DefaultInfo].files_to_run.executable
 
-    py_runtime = ctx.toolchains[TARGET_TOOLCHAIN_TYPE].py3_runtime
+    interpreter = ctx.toolchains[EXEC_TOOLS_TOOLCHAIN_TYPE].exec_tools.exec_interpreter[DefaultInfo]
 
     args = _args(ctx)
     args.add_all([
@@ -104,7 +104,7 @@ def _lock_impl(ctx):
     args.add_all(ctx.files.constraints, before_each = "--constraints")
     args.add_all(ctx.attr.args)
 
-    python = py_runtime.interpreter if py_runtime.interpreter else py_runtime.interpreter_path
+    python = interpreter.files_to_run.executable or "python"
     args.add("--python", python)
     args.add_all(srcs)
 
@@ -134,7 +134,10 @@ def _lock_impl(ctx):
         mnemonic = "PyRequirementsLockUv",
         outputs = [output],
         arguments = [args.run_shell],
-        tools = [uv],
+        tools = [
+            uv,
+            interpreter.files_to_run,
+        ],
         progress_message = "Creating a requirements.txt with uv: //{}:{}".format(
             ctx.label.package,
             ctx.label.name,
@@ -149,9 +152,7 @@ def _lock_impl(ctx):
             env = ctx.attr.env,
             srcs = depset(
                 srcs + [uv] + ctx.files.build_constraints + ctx.files.constraints,
-                transitive = [
-                    py_runtime.files,
-                ],
+                transitive = [interpreter.files],
             ),
         ),
     ]
@@ -240,9 +241,8 @@ The string to input for the 'uv pip compile'.
         ),
     },
     toolchains = [
+        EXEC_TOOLS_TOOLCHAIN_TYPE,
         UV_TOOLCHAIN_TYPE,
-        # FIXME @aignas 2025-03-17: should this be instead EXEC_TOOLCHAIN_TYPE?
-        TARGET_TOOLCHAIN_TYPE,
     ],
     cfg = _python_version_transition,
 )