Document build from pypi archive

README.rst

@@ -76,9 +76,9 @@ following bash scripts:
 
 See ``docker_build_wrap.sh`` to review the order of script sourcing.
 
-See the definition of ``build_wheel`` in ``multibuild/travis_linux_steps.sh``
-for the environment variables passed from travis-ci to the Manylinux1
-container.
+See the definition of ``build_multilinux`` in
+``multibuild/travis_linux_steps.sh`` for the environment variables passed from
+travis-ci to the Manylinux1 container.
 
 Once in the container, after sourcing the scripts above, the wrapper runs the
 real ``build_wheel`` function, which now comes (by default) from
@@ -113,9 +113,14 @@ default the function that is run on OSX, and in the Manylinux container for
 the build phase, is defined in ``multibuild/common_utils.sh``.  You can
 override the default function in the project ``config.sh`` file (see below).
 
-Typically, you can get away with leaving the default ``build_wheel`` function,
-but you may need to define a ``pre_build`` function in ``config.sh``.  The
-default ``build_wheel`` function will call the ``pre_build`` function, if
+If you are building a wheel from pypi, rather than from a source repository,
+you can use the ``build_index_wheel`` command, again defined in
+``multibuild/common_utils.sh``.
+
+Typically, you can get away with leaving the default ``build_wheel`` /
+``build_index_wheel`` functions to do their thing, but you may need to define
+a ``pre_build`` function in ``config.sh``.  The default ``build_wheel`` and
+``build_index_wheel`` functions will call the ``pre_build`` function, if
 defined, before building the wheel, so ``pre_build`` is a good place to build
 any required libraries.
 
@@ -262,6 +267,21 @@ To use these scripts
             --no-update-index
             wheels
 
+  The example above is for a project building from a git submodule.  If you
+  aren't building from a submodule, but want to use ``pip`` to build from a
+  source archive on https://pypi.org or similar, replace the first few lines
+  of the ``.travis.yml`` file with something like::
+
+    env:
+        global:
+            # Instead of REPO_DIR, BUILD_COMMIT
+            - PROJECT_SPEC="tornado==4.1.1"
+
+  then your ``install`` section could look something like this::
+
+    install:
+        - build_index_wheel $PROJECT_SPEC
+
 * Next create a ``config.sh`` for your project, that fills in any steps you
   need to do before building the wheel (such as building required libraries).
   You also need this file to specify how to run your tests::