[tips] document alpine compilation

R1/source/tips/alpine/index.rst

+.. _alpine:
+
+Compiling on Alpine
+===================
+
+There are at least two gotchas on Alpine Linux to compile Varnish.
+
+- `jemalloc` isn't present on that platform so you will need to pass
+  `--without-jemalloc` to `configure` so the build system uses the default
+  libc's `malloc` functions.
+- `libexecinfo` has issues making the panics useless, it is recommended to use
+  `libunwind` instead, by passing `--with-unwind` to `configure`.

R1/source/tips/index.rst

@@ -23,3 +23,4 @@ errors. The :ref:`HowTo <contribdoc>` section will help you get started.
    vcl/index
    varnishlog/index
    migration/index
+   alpine/index