Automate setting of the development GN3 repo

* When developing the GN2 code, there are times we need to use the
  latest code in GN3, and rather than manually editing the
  `bin/genenetwork` file every time we need that, this commit enables
  the use of an environment variable.

  In this case, launching the application with something like:

    $ env GN3_DEV_REPO_PATH="$HOME/genenetwork3" ...\
      ./bin/genenetwork2 ./the_settings.py -gunicorn-dev

  will add the path to the development version to the PYTHONPATH. If
  the GN3_DEV_REPO_PATH variable is not set, then the PYTHONPATH is
  not altered, and would be as if there is no development version of
  GN3 in use.

1 files changed, 2 insertions, 0 deletions

diff --git a/bin/genenetwork2 b/bin/genenetwork2
index 0a2c18cf..1b933e80 100755
--- a/bin/genenetwork2
+++ b/bin/genenetwork2
@@ -149,6 +149,8 @@ fi
 # We may change this one:
 export PYTHONPATH=$PYTHON_GN_PATH:$GN2_BASE_DIR/wqflask:$GN3_PYTHONPATH:$PYTHONPATH
 
+export PYTHONPATH="${GN3_DEV_REPO_PATH:+$GN3_DEV_REPO_PATH:}:${PYTHONPATH}"
+
 # Our UNIX TMPDIR defaults to /tmp - change this on a shared server
 if [ -z $TMPDIR ]; then
     TMPDIR="/tmp"