Fix path to licence-checker on Bazel 7

licence-checker/BUILD

@@ -5,6 +5,7 @@
 package(default_visibility = ["//visibility:public"])
 
 load("@lowrisc_misc_linters_pip//:requirements.bzl", "requirement")
+load("@rules_python//python:py_binary.bzl", "py_binary")
 
 py_binary(
     name = "licence-checker",

rules/licence-checker-runner.template.sh

@@ -3,6 +3,10 @@
 # Licensed under the Apache License, Version 2.0, see LICENSE for details.
 # SPDX-License-Identifier: Apache-2.0
 
+# Remember the runfiles dir since this is what paths like "@@LICENCE_CHECKER@@"
+# and "@@CONFIG@@" are relative to once we `cd` elsewhere.
+RUNFILES_DIR="$PWD"
+
 WORKSPACE="@@WORKSPACE@@"
 
 if [[ ! -z "${WORKSPACE}" ]]; then
@@ -16,4 +20,4 @@ else
     exit 1
 fi
 
-"@@LICENCE_CHECKER@@" --config="@@CONFIG@@" "$@"
+"${RUNFILES_DIR}/@@LICENCE_CHECKER@@" --config="${RUNFILES_DIR}/@@CONFIG@@" "$@"

rules/rules.bzl

@@ -18,34 +18,20 @@ def _licence_check_impl(ctx):
             },
         )
 
-    # Hack to make Bazel build the checker correctly.
-    #
-    # Bazel py_binaries require a .runfiles directory to be present, but for
-    # some reason or another it does not provide a good way to extract those
-    # for building as a dependency from a PyInfo provider.
-    #
-    # https://github.com/bazelbuild/bazel/issues/7357
-    checker = ctx.actions.declare_file(ctx.label.name + ".checker-witness")
-    ctx.actions.run_shell(
-        tools = [ctx.executable.licence_check],
-        outputs = [checker],
-        command = 'touch "{}"'.format(checker.path),
-    )
-
     workspace = ctx.file.workspace.path if ctx.file.workspace else ""
     script = ctx.actions.declare_file(ctx.label.name + ".bash")
     ctx.actions.expand_template(
         template = ctx.file._runner,
         output = script,
         substitutions = {
-            "@@LICENCE_CHECKER@@": ctx.executable.licence_check.path,
-            "@@CONFIG@@": config.path,
+            "@@LICENCE_CHECKER@@": ctx.executable.licence_check.short_path,
+            "@@CONFIG@@": config.short_path,
             "@@WORKSPACE@@": workspace,
         },
         is_executable = True,
     )
 
-    files = [config, checker]
+    files = [config]
     if ctx.file.workspace:
         files.append(ctx.file.workspace)
 
@@ -78,7 +64,7 @@ licence_check_attrs = {
     ),
     "licence_check": attr.label(
         default = "//licence-checker",
-        cfg = "host",
+        cfg = "exec",
         executable = True,
         doc = "The licence checker executable",
     ),