[WORKSPACE, docs] Add hermetic dependency on Lua 5.1.

With this change, Lua is no longer a system prerequisite, but instead
it will be downloaded and built from source.

.travis.yml

@@ -10,8 +10,6 @@ language: c++
 addons:
   apt:
     packages:
-      - lua5.1
-      - liblua5.1-0-dev
       - libffi-dev
       - gettext
       - freeglut3-dev

README.md

@@ -148,7 +148,6 @@ software libraries, which we ship in several different ways:
  * Several additional libraries are required but are not shipped in any form;
    they must be present on your system:
    * SDL 2
-   * Lua 5.1 (later versions might work, too)
    * gettext (required by `glib`)
    * OpenGL: A hardware driver and library are needed for hardware-accelerated
      human play. The headless library that machine learning agents will want to

RELEASE_NOTES.md

@@ -12,6 +12,8 @@
     log messages are emitted via the setting 'logLevel'.
 4.  Update the ioq3 upstream code to the [latest
     state](https://github.com/ioquake/ioq3/tree/29db64070aa0bae49953bddbedbed5e317af48ba).
+5.  Lua 5.1 is now downloaded and built from source, and is thus no longer a
+    required local dependency.
 
 ### Bug Fixes:
 

WORKSPACE

@@ -86,13 +86,18 @@ new_http_archive(
     ],
 )
 
-# TODO: Replace with hermetic build
-new_local_repository(
-    name = "lua_system",
+new_http_archive(
+    name = "lua_archive",
     build_file = "lua.BUILD",
-    path = "/usr",
+    sha256 = "2640fc56a795f29d28ef15e13c34a47e223960b0240e8cb0a82d9b0738695333",
+    strip_prefix = "lua-5.1.5/src",
+    urls = [
+        "https://mirror.bazel.build/www.lua.org/ftp/lua-5.1.5.tar.gz",
+        "https://www.lua.org/ftp/lua-5.1.5.tar.gz",
+    ],
 )
 
+# TODO: Replace with hermetic build
 new_local_repository(
     name = "sdl_system",
     build_file = "sdl.BUILD",

deepmind/lua/BUILD

@@ -5,7 +5,7 @@ licenses(["restricted"])  # GPLv2
 
 package(default_visibility = ["//visibility:public"])
 
-LUA_VERSION = "@lua_system//:lua"
+LUA_VERSION = "@lua_archive//:lua"
 
 cc_library(
     name = "lua",

docs/users/build.md

@@ -16,9 +16,8 @@ modern compiler. GCC 4.8 should suffice.
 Instructions for installing Bazel can be found in the [Bazel install
 guide](https://docs.bazel.build/versions/master/install.html).
 
-You may need to deal with some details concerning Lua and Python dependencies.
-Those are documented in a [separate section](#lua-and-python-dependencies)
-below.
+You may need to deal with some details concerning Python dependencies. Those
+are documented in a [separate section](#python-dependencies) below.
 
 ## Step-by-step instructions for building and running
 
@@ -31,9 +30,8 @@ below.
      Tested on Debian 8.6 (Jessie) and Ubuntu 14.04 (Trusty) and newer.
 
      ```shell
-     $ sudo apt-get install lua5.1 liblua5.1-0-dev libffi-dev gettext \
-           freeglut3-dev libsdl2-dev libosmesa6-dev python-dev python-numpy \
-           python-pil realpath
+     $ sudo apt-get install libffi-dev gettext freeglut3-dev libsdl2-dev \
+           libosmesa6-dev python-dev python-numpy python-pil realpath
      ```
 
    * On Red Hat Enterprise Linux Server:
@@ -42,25 +40,25 @@ below.
      some modifications of the package installation commands on Centos 6.
 
      ```shell
-     sudo yum -y install unzip java-1.8.0-openjdk lua lua-devel libffi-devel \
-         java-1.8.0-openjdk-devel gcc gcc-c++ freeglut-devel SDL2 SDL2-devel \
-         mesa-libOSMesa-devel python-devel python-imaging zip numpy
+     sudo yum -y install unzip java-1.8.0-openjdk libffi-devel gcc gcc-c++ \
+         java-1.8.0-openjdk-devel freeglut-devel python-devel python-imaging \
+         SDL2 SDL2-devel mesa-libOSMesa-devel zip numpy
      ```
 
    * On SUSE Linux:
 
      Tested on SUSE Linux Enterprise Server 12.
 
      ```shell
-     sudo zypper --non-interactive install gcc gcc-c++ lua java-1_8_0-openjdk \
-         java-1_8_0-openjdk-devel lua-devel python-devel python-numpy-devel \
-         python-imaging libSDL-devel libOSMesa-devel freeglut-devel
+     sudo zypper --non-interactive install gcc gcc-c++ java-1_8_0-openjdk \
+         java-1_8_0-openjdk-devel libOSMesa-devel freeglut-devel libSDL-devel \
+         python-devel python-numpy-devel python-imaging
      ```
 
 3. [Clone or download *DeepMind Lab*](https://github.com/deepmind/lab).
 
-4. If necessary, edit `lua.BUILD` and `python.BUILD` according to the [Lua and
-   Python instructions](#lua-and-python-dependencies) below.
+4. If necessary, edit `python.BUILD` according to the [Python
+   instructions](#python-dependencies) below.
 
 5. Build *DeepMind Lab* and run a random agent. (Use the `-c opt` flag to enable
    optimizations.)
@@ -84,33 +82,18 @@ with *DeepMind Lab*.
 The random agent target `:python_random_agent` has a number of optional command line
 arguments. Run `bazel run :random_agent -- --help` to see those.
 
-## Lua and Python dependencies
+## Python dependencies
 
 *DeepMind Lab* does not include every dependency hermetically. In particular,
-Lua and Python are not included, but instead must already be installed on your
-system. This means that depending on the details of where those libraries are
+Python is not included, but instead must already be installed on your
+system. This means that depending on the details of where that library is
 installed, you may need to adjust the Bazel build rules in
-[`lua.BUILD`](../../lua.BUILD) and [`python.BUILD`](../../python.BUILD) to
-locate them correctly.
+[`python.BUILD`](../../python.BUILD) to locate it correctly.
 
 The default build rules should work for Debian and Ubuntu. Note that paths in
 the build rules are relative to the root path specified in the
 [`WORKSPACE`](../../WORKSPACE) file (which is `"/usr"` by default).
 
-Lua, for example, is installed directly in `/usr/include` on some systems like
-Red Hat and SUSE Linux. Therefore you need to edit `lua.BUILD` to reflect that
-location (or rather, the absence of a special location):
-
-```python
-cc_library(
-    name = "lua",
-    linkopts = ["-llua"],
-    visibility = ["//visibility:public"],
-)
-```
-The output of `pkg-config lua --libs --cflags` might be helpful to find the
-right include directories and linker options.
-
 Python requires two separate dependencies: The CPython extension API, and NumPy.
 If, say, NumPy is installed in a custom location, like it is on SUSE Linux, you
 need to add the files from that location and set an include search path

lua.BUILD

@@ -1,13 +1,26 @@
 # Description:
 #   Build rule for Lua 5.1.
-#   Compiler and linker flags found with `pkg-config --cflags --libs lua5.1`.
-#   The package name and the resulting flags may vary from platform to platform,
-#   cf. 'How to build DeepMind Lab' in build.md.
 
 cc_library(
     name = "lua",
-    hdrs = glob(["include/lua5.1/*.h"]),
-    includes = ["include/lua5.1"],
-    linkopts = ["-llua5.1"],
+    srcs = glob(
+        include = [
+            "*.c",
+            "*.h",
+        ],
+        exclude = [
+            "lauxlib.h",
+            "lua.c",
+            "lua.h",
+            "luac.c",
+            "lualib.h",
+            "print.c",
+        ],
+    ),
+    hdrs = [
+        "lauxlib.h",
+        "lua.h",
+        "lualib.h",
+    ],
     visibility = ["//visibility:public"],
 )