Merge branch 'stable-2.14' into stable-2.15

* stable-2.14:
  Bazel: Fix build on Alpine Linux
  Make bzl files compatible with mutating behavior of += on lists

Change-Id: I242c26fa7ef5c532c78bd5dc06d9f332e6a51f00

tools/bzl/asciidoc.bzl

@@ -255,7 +255,7 @@ def _asciidoc_zip_impl(ctx):
   cmd = [
     "p=$PWD",
     "rm -rf %s" % tmpdir,
-    "mkdir %s" % tmpdir,
+    "mkdir -p %s/%s/" % (tmpdir, ctx.attr.directory),
     "unzip -q %s -d %s/%s/" % (ctx.file.src.path, tmpdir, ctx.attr.directory),
   ]
   for r in ctx.files.resources: