new buildpack env standard

bin/compile

@@ -15,7 +15,7 @@ BIN_DIR=$(cd $(dirname $0); pwd) # absolute path
 ROOT_DIR=$(dirname $BIN_DIR)
 BUILD_DIR=$1
 CACHE_DIR=$2
-ENV_FILE=$3
+ENV_DIR=$3
 
 
 CACHED_DIRS=".heroku"
@@ -25,8 +25,7 @@ VIRTUALENV_LOC=".heroku/venv"
 LEGACY_TRIGGER="lib/python2.7"
 PROFILE_PATH="$BUILD_DIR/.profile.d/python.sh"
 
-# Python version. This will be used in the future to specify custom Pythons.
-DEFAULT_PYTHON_VERSION="python-2.7.4"
+DEFAULT_PYTHON_VERSION="python-2.7.6"
 PYTHON_EXE="/app/.heroku/python/bin/python"
 PIP_VERSION="1.3.1"
 DISTRIBUTE_VERSION="0.6.36"
@@ -103,6 +102,11 @@ if [ ! -f requirements.txt ]; then
   echo "-e ." > requirements.txt
 fi
 
+# Sticky runtimes.
+if [ -f $CACHE_DIR/.heroku/python-version ]; then
+  DEFAULT_PYTHON_VERSION=$(cat $CACHE_DIR/.heroku/python-version)
+fi
+
 # If no runtime given, assume default version.
 if [ ! -f runtime.txt ]; then
   puts-step "No runtime.txt provided; assuming $DEFAULT_PYTHON_VERSION."

bin/utils

@@ -59,6 +59,22 @@ function deep-rm (){
   find -H $1 -maxdepth 1 -name '.*' -a \( -type d -o -type f -o -type l \) -exec rm -fr '{}' \;
 }
 
-function sub-env (){
-   (export $(egrep -v '^(GIT_DIR|PYTHONHOME|PYTHONPATH|LD_LIBRARY_PATH|LIBRARY_PATH|PATH)' $ENV_FILE); $1)
-}
+
+sub-env() {
+
+  WHITELIST=${2:-''}
+  BLACKLIST=${3:-'^(GIT_DIR|PYTHONHOME|PYTHONPATH|LD_LIBRARY_PATH|LIBRARY_PATH|PATH)$'}
+
+  (
+    if [ -d "$ENV_DIR" ]; then
+      for e in $(ls $ENV_DIR); do
+        echo "$e" | grep -E "$WHITELIST" | grep -qvE "$BLACKLIST" &&
+        export "$e=$(cat $ENV_DIR/$e)"
+        :
+      done
+    fi
+
+    $1
+
+  )
+}