[doc] updated contribute for local dependencies and tests Fixes #214

doc/contribute.rst

@@ -125,6 +125,38 @@ Will run all the tests verbosely and not capture the outputs of the test. The
 `-s` option is mandatory if there's a need to brake in the code using python's
 debugger.
 
+If you wish to build your own dependency packages (assume we wish to build our own `beat.core`, `beat.cmdline` and `beat.backend.python`) and run the tests, please do the following:
+
+- In `buildout.cfg` add the line: ::
+
+    dependent-scripts = true
+
+- In `development.cfg` add the following lines: ::
+
+    extensions = mr.developer
+    auto-checkout = *
+    develop = src/beat.backend.python
+              src/beat.core
+              src/beat.cmdline
+              .
+
+    [sources]
+    beat.core = git https://gitlab.idiap.ch/beat/beat.core.git
+    beat.cmdline = git https://gitlab.idiap.ch/beat/beat.cmdline.git
+    beat.backend.python = git https://gitlab.idiap.ch/beat/beat.backend.python.git``
+
+Make sure you have removed `beat.core`, `beat.cmdline` and `beat.backend.python` from your conda environment! ::
+
+    $ conda list # check
+    $ conda remove <package>
+
+Then rebuild all packages (you can delete the bin/ folder to make sure it's rebuilt): ::
+
+    $ buildout -c development.cfg
+
+Now running your tests would require pytest to use the current environment and use your dependency packages: ::
+
+    $ ./bin/python -m pytest -sv
 
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