diff --git a/.travis.yml b/.travis.yml
index e8a9193f9b7c9..b48f6d834b62d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,20 +2,29 @@ language: python
 
 python:
   - 2.6
-  - 3.3
 
 env:
   global:
-    - NOSE_ARGS="not slow" # need at least this so travis page will show env column
+    - secure: "O04RU5QRKEDL/SrIWEsVe8O+1TxZqZQSa28Sd+Fz48NW/XddhefYyxzqcUXh\nk/NjWMqknJRQhApLolBianVpsE577OTllzlcyKn3nUL6hjOXcoszGaYray7S\niNGKGyO8xrtB/ZQDtmupz0ksK8sLoCTscdiGotFulczbx0zt+4g="
+    - secure: "PUJ9nC1/v2vpFUtELSoSjI53OHCVXfFTb8+t5lIGIqHtjUBkhiJSNPfCv8Bx\ndsdrx30qP8KsSceYzaa/bog6p8YNU1iih23S0KbjucutvA0LNHBTNvnxmjBR\nSJfKd5FmwnXvizRyghYBzmQ3NmGO7ADw2DBwKOhgGMqCHZ8Tlc8="
+    - secure: "IDcMrCCW+6pgJtsI3Q163OPc0iec1ogpitaqiRhHcrEBUCXZgVeclOeiZBlw\n/u+uGyW/O0NhHMaFXKB8BdDVwlQEEHv48syN6npS/A5+O6jriWKL4ozttOhE\npOlu+yLhHnEwx6wZVIHRTVn+t1GkOrjlBcjaQi+Z13G3XmDaSG8="
+    - secure: "Zu9aj0dTGpvMqT/HqBGQgDYl/v5ubC7lFwfE8Fqb0N1UVXqbpjXnNH/7oal1\nUsIT7klO++LWm+LxsP/A1FWENTSgdYe99JQtNyauW+0x5YR1JTuDJ8atDgx9\nSq66CaVpS5t+ov7UVm2bKSUX+1S8+8zGbIDADrMxEzYEMF7WoGM="
+    - secure: "AfIvLxvCxj22zrqg3ejGf/VePKT2AyGT9erYzlKpBS0H8yi5Pp1MfmJjhaR4\n51zBtzqHPHiIEY6ZdE06o9PioMWkXS+BqJNrxGSbt1ltxgOFrxW5zOpwiFGZ\nZOv1YeFkuPf8PEsWT7615mdydqTQT7B0pqUKK/d6aka4TQ/tg5Q="
+    - secure: "EM4ySBUusReNu7H1QHXvjnP/J1QowvfpwEBmjysYxJuq7KcG8HhhlfpUF+Gh\nLBzLak9QBA67k4edhum3qtKuJR5cHuja3+zuV8xmx096B/m96liJFTrwZpea\n58op3W6ZULctEpQNgIkyae20bjxl4f99JhZRUlonoPfx/rBIMFc="
+    - secure: "pgMYS/6MQqDGb58qdzTJesvAMmcJWTUEEM8gf9rVbfqfxceOL4Xpx8siR9B2\nC4U4MW1cHMPP3RFEb4Jy0uK49aHH10snwZY1S84YPPllpH5ZFXVdN68OayNj\nh4k5N/2hhaaQuJ6Uh8v8s783ye4oYTOW5RJUFqQu4QdG4IkTIMs="
+
+    - NOSE_ARGS="not slow" UPLOAD=true
 
 matrix:
   include:
     - python: 2.7
-      env: NOSE_ARGS="not network"  LOCALE_OVERRIDE="zh_CN.GB18030"
+      env: NOSE_ARGS="slow and not network"  LOCALE_OVERRIDE="zh_CN.GB18030" FULL_DEPS=true UPLOAD=false
     - python: 2.7
-      env: NOSE_ARGS="not slow" FULL_DEPS=true
+      env: NOSE_ARGS="not slow" FULL_DEPS=true UPLOAD=true
     - python: 3.2
-      env: NOSE_ARGS="not slow" FULL_DEPS=true
+      env: NOSE_ARGS="not slow" FULL_DEPS=true UPLOAD=true
+    - python: 3.3
+      env: NOSE_ARGS="not slow" UPLOAD=true
 
 # allow importing from site-packages,
 # so apt-get python-x works for system pythons
@@ -26,11 +35,14 @@ virtualenv:
 before_install:
   - echo "Waldo1"
   - echo $VIRTUAL_ENV
+  - df
   - date
-  - export PIP_ARGS=-q # comment this this to debug travis install issues
-  - export APT_ARGS=-qq # comment this to debug travis install issues
+  # - export PIP_ARGS=-q # comment this this to debug travis install issues
+  # - export APT_ARGS=-qq # comment this to debug travis install issues
   # - set -x # enable this to see bash commands
-  - source ci/before_install.sh # we need to source this to bring in the env
+  - export ZIP_FLAGS=-q # comment this to debug travis install issues
+  - source ci/envars.sh # we need to source this to bring in the envars
+  - ci/before_install.sh
   - python -V
 
 install:
@@ -43,3 +55,4 @@ script:
 
 after_script:
   - ci/print_versions.py
+  - ci/after_script.sh
diff --git a/ci/before_install.sh b/ci/before_install.sh
index 9561c713d0f2e..677ddfa642f80 100755
--- a/ci/before_install.sh
+++ b/ci/before_install.sh
@@ -1,28 +1,36 @@
 #!/bin/bash
 
+# If envars.sh determined we're running  in an authorized fork
+# and the user opted in to the network cache,and that cached versions
+# are available on the cache server, download and deploy the cached
+# files to the local filesystem
+
 echo "inside $0"
 
 # overview
-if [ ${TRAVIS_PYTHON_VERSION} == "3.3" ]; then
-    sudo add-apt-repository -y ppa:doko/ppa # we get the py3.3 debs from here
-fi
-
 sudo apt-get update $APT_ARGS # run apt-get update for all versions
 
-# # hack for broken 3.3 env
-# if [ x"$VIRTUAL_ENV" == x"" ]; then
-#     VIRTUAL_ENV=~/virtualenv/python$TRAVIS_PYTHON_VERSION_with_system_site_packages;
-# fi
+if  $PLEASE_TRAVIS_FASTER ; then
+    echo "Faster? well... I'll try."
+
+    if $CACHE_FILE_AVAILABLE ;  then
+        echo retrieving "$CACHE_FILE_URL";
+
+        wget -q "$CACHE_FILE_URL" -O "/tmp/_$CYTHON_HASH.zip";
+        unzip $ZIP_FLAGS /tmp/_"$CYTHON_HASH.zip" -d "$BUILD_CACHE_DIR";
+        rm -f /tmp/_"$CYTHON_HASH.zip"
+        # copy cythonized c files over
+        cp -R "$BUILD_CACHE_DIR"/pandas/*.c pandas/
+        cp -R "$BUILD_CACHE_DIR"/pandas/src/*.c pandas/src/
+    fi;
+    echo "VENV_FILE_AVAILABLE=$VENV_FILE_AVAILABLE"
+    if $VENV_FILE_AVAILABLE ; then
+        echo "getting venv"
+        wget -q $VENV_FILE_URL -O  "/tmp/venv.zip";
+        sudo unzip $ZIP_FLAGS -o /tmp/venv.zip -d "/";
+        sudo chown travis -R "$VIRTUAL_ENV"
+        rm -f /tmp/_"$CYTHON_HASH.zip"
+    fi;
+fi
 
-# # we only recreate the virtualenv for 3.x
-# # since the "Detach bug" only affects python3
-# # and travis has numpy preinstalled on 2.x which is quicker
-# _VENV=$VIRTUAL_ENV # save it
-# if [ ${TRAVIS_PYTHON_VERSION:0:1} == "3" ] ; then
-#     deactivate # pop out of any venv
-#     sudo pip install virtualenv==1.8.4 --upgrade
-#     sudo apt-get install $APT_ARGS python3.3 python3.3-dev
-#     sudo rm -Rf $_VENV
-#     virtualenv -p python$TRAVIS_PYTHON_VERSION $_VENV --system-site-packages;
-#     source $_VENV/bin/activate
-# fi
+true # never fail because bad things happened here
diff --git a/ci/envars.sh b/ci/envars.sh
new file mode 100755
index 0000000000000..14ac783af9631
--- /dev/null
+++ b/ci/envars.sh
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+# This must be sourced by .travis.yml, so any envars exported here will
+# be available to the rest of the build stages
+
+# - computes a hash based on the cython files in the codebade
+# - retrieves the decrypted key if any for all whitelisted forks
+# - checks whether the user optd int to use the cache
+# - if so, check for availablity of cache files on the server, based on hash
+# - set envars to control what the following scripts do
+
+# at most one of these will decrypt, so the end result is that $STORE_KEY
+# either holds a single key or does not
+export STORE_KEY="$STORE_KEY0""$STORE_KEY1""$STORE_KEY2""$STORE_KEY3""$STORE_KEY4"
+export STORE_KEY="$STORE_KEY""$STORE_KEY5""$STORE_KEY6""$STORE_KEY7"
+
+export CYTHON_HASH=$(find pandas | grep -P '\.(pyx|pxd)$'  | sort \
+     | while read N; do echo $(tail -n+1 $N | md5sum ) ;done | md5sum| cut -d ' ' -f 1)
+
+export CYTHON_HASH=$CYTHON_HASH-$TRAVIS_PYTHON_VERSION
+
+# where the cache files live on the server
+export CACHE_FILE_URL="https://cache27-pypandas.rhcloud.com/static/$STORE_KEY/$CYTHON_HASH.zip"
+export VENV_FILE_URL="https://cache27-pypandas.rhcloud.com/static/$STORE_KEY/venv-$TRAVIS_PYTHON_VERSION.zip"
+export CACHE_FILE_STORE_URL="https://cache27-pypandas.rhcloud.com/store/$STORE_KEY"
+
+echo "Hashing:"
+find pandas | grep -P '\.(pyx|pxd)$'
+echo "Key: $CYTHON_HASH"
+
+export CACHE_FILE_AVAILABLE=false
+export VENV_FILE_AVAILABLE=false
+export PLEASE_TRAVIS_FASTER=false
+
+# check whether the user opted in to use the cache via commit message
+if [ x"$(git log --format='%s' -n 1 | grep PLEASE_TRAVIS_FASTER | wc -l)" != x"0" ]; then
+    export PLEASE_TRAVIS_FASTER=true
+fi;
+if [ x"$(git log --format='%s' -n 1 | grep PTF | wc -l)" != x"0" ]; then
+    export PLEASE_TRAVIS_FASTER=true
+fi;
+
+if $PLEASE_TRAVIS_FASTER; then
+
+    # check whether the files exists on the server
+    curl -s -f -I "$CACHE_FILE_URL"  #  silent, don;t expose key
+    if [ x"$?" == x"0" ] ; then
+        export CACHE_FILE_AVAILABLE=true;
+    fi
+
+
+    curl -s -f -I "$VENV_FILE_URL" #  silent, don;t expose key
+    if [ x"$?" == x"0" ] ; then
+        export VENV_FILE_AVAILABLE=true;
+    fi
+
+    # the pandas build cache machinery needs this set, and the directory created
+    export BUILD_CACHE_DIR="/tmp/build_cache"
+    mkdir "$BUILD_CACHE_DIR"
+fi;
+
+# debug
+echo "PLEASE_TRAVIS_FASTER=$PLEASE_TRAVIS_FASTER"
+echo "CACHE_FILE_AVAILABLE=$CACHE_FILE_AVAILABLE"
+echo "VENV_FILE_AVAILABLE=$VENV_FILE_AVAILABLE"
+
+true
diff --git a/ci/install.sh b/ci/install.sh
index 7fe425e055589..0045a6c3c86f6 100755
--- a/ci/install.sh
+++ b/ci/install.sh
@@ -1,75 +1,128 @@
 #!/bin/bash
 
+# There are 2 distinct pieces that get zipped and cached
+# - The venv site-packages dir including the installed dependencies
+# - The pandas build artifacts, using the build cache support via
+#   scripts/use_build_cache.py
+#
+# if the user opted in to use the cache and we're on a whitelisted fork
+# - if the server doesn't hold a cached version of venv/pandas build,
+#   do things the slow way, and put the results on the cache server
+#   for the next time.
+# -  if the cache files are available, instal some necessaries via apt
+#    (no compiling needed), then directly goto script and collect 200$.
+#
+
 echo "inside $0"
-# Install Dependencies
+# Install Dependencie
+SITE_PKG_DIR=$VIRTUAL_ENV/lib/python$TRAVIS_PYTHON_VERSION/site-packages
+echo "Using SITE_PKG_DIR: $SITE_PKG_DIR"
 
 # workaround for travis ignoring system_site_packages in travis.yml
 rm -f $VIRTUAL_ENV/lib/python$TRAVIS_PYTHON_VERSION/no-global-site-packages.txt
 
-# Hard Deps
-pip install $PIP_ARGS --use-mirrors cython nose python-dateutil pytz
-
-# try and get numpy as a binary deb
+if [ x"$LOCALE_OVERRIDE" != x"" ]; then
+    # make sure the locale is available
+    # probably useless, since you would need to relogin
+    sudo locale-gen "$LOCALE_OVERRIDE"
+fi;
 
-# numpy is preinstalled on 2.x
-# if [ ${TRAVIS_PYTHON_VERSION} == "2.7" ]; then
-#     sudo apt-get $APT_ARGS install python-numpy;
-# fi
+#scipy is not included in the cached venv
+if [ x"$FULL_DEPS" == x"true" ] ; then
+   # for pytables gets the lib as well
+   sudo apt-get $APT_ARGS install libhdf5-serial-dev;
 
-if [ ${TRAVIS_PYTHON_VERSION} == "3.2" ]; then
-    sudo apt-get $APT_ARGS install python3-numpy;
-elif [ ${TRAVIS_PYTHON_VERSION} == "3.3" ]; then # should be >=3,3
-    pip $PIP_ARGS install numpy==1.7.0;
-else
-    pip $PIP_ARGS install numpy==1.6.1;
+   if [ ${TRAVIS_PYTHON_VERSION} == "3.2" ]; then
+       sudo apt-get $APT_ARGS install python3-scipy
+   elif [ ${TRAVIS_PYTHON_VERSION} == "2.7" ]; then
+       sudo apt-get $APT_ARGS install python-scipy
+   fi
 fi
 
-# Optional Deps
-if [ x"$FULL_DEPS" == x"true" ]; then
-    echo "Installing FULL_DEPS"
-    if [ ${TRAVIS_PYTHON_VERSION} == "2.7" ]; then
-        sudo apt-get $APT_ARGS install python-scipy;
-    fi
+# Everything installed inside this clause into site-packages
+# will get included in the cached venv downloaded from the net
+# in PTF mode
+if ( ! $VENV_FILE_AVAILABLE ); then
+    echo "Running full monty"
+    # Hard Deps
+    pip install $PIP_ARGS  nose python-dateutil pytz
+    pip install $PIP_ARGS  cython
 
-    if [ ${TRAVIS_PYTHON_VERSION} == "3.2" ]; then
-        sudo apt-get $APT_ARGS install python3-scipy;
+    if [ ${TRAVIS_PYTHON_VERSION} == "3.3" ]; then # should be >=3,3
+        pip install $PIP_ARGS numpy==1.7.0
+    elif [ ${TRAVIS_PYTHON_VERSION} == "3.2" ]; then
+        # sudo apt-get $APT_ARGS install python3-numpy; # 1.6.2 or precise
+        pip install $PIP_ARGS numpy==1.6.1
+    else
+        pip install $PIP_ARGS numpy==1.6.1
     fi
 
-    if [ ${TRAVIS_PYTHON_VERSION:0:1} == "2" ]; then
-        sudo apt-get $APT_ARGS install libhdf5-serial-dev;
-        pip install numexpr
-        pip install tables
+    # Optional Deps
+    if [ x"$FULL_DEPS" == x"true" ]; then
+        echo "Installing FULL_DEPS"
+        pip install $PIP_ARGS  cython
+
+        if [ ${TRAVIS_PYTHON_VERSION:0:1} == "2" ]; then
+            # installed explicitly above, to get the library as well
+        #    sudo apt-get $APT_ARGS install libhdf5-serial-dev;
+            pip install numexpr
+            pip install tables
+            pip install $PIP_ARGS xlwt
+        fi
+
+        pip install $PIP_ARGS matplotlib
+        pip install $PIP_ARGS openpyxl
+        pip install $PIP_ARGS xlrd>=0.9.0
+        pip install $PIP_ARGS 'http://downloads.sourceforge.net/project/pytseries/scikits.timeseries/0.91.3/scikits.timeseries-0.91.3.tar.gz?r='
+        pip install $PIP_ARGS patsy
+
+        # fool statsmodels into thinking pandas was already installed
+        # so it won't refuse to install itself. We want it in the zipped venv
+
+        mkdir  $SITE_PKG_DIR/pandas
+        touch $SITE_PKG_DIR/pandas/__init__.py
+        echo "version='0.10.0-phony'" >  $SITE_PKG_DIR/pandas/version.py
+        pip install $PIP_ARGS git+git://github.com/statsmodels/statsmodels@c9062e43b8a5f7385537ca95#egg=statsmodels
+
+        rm -Rf $SITE_PKG_DIR/pandas # scrub phoney pandas
     fi
 
-    pip install $PIP_ARGS --use-mirrors openpyxl matplotlib;
-    pip install $PIP_ARGS --use-mirrors xlrd xlwt;
-    pip install $PIP_ARGS 'http://downloads.sourceforge.net/project/pytseries/scikits.timeseries/0.91.3/scikits.timeseries-0.91.3.tar.gz?r='
-fi
+    # pack up the venv and cache it
+    if [ x"$STORE_KEY" != x"" ] && $UPLOAD; then
+        VENV_FNAME="venv-$TRAVIS_PYTHON_VERSION.zip"
 
-if [ x"$VBENCH" == x"true" ]; then
-    if [ ${TRAVIS_PYTHON_VERSION:0:1} == "2" ]; then
-        sudo apt-get $APT_ARGS install libhdf5-serial-dev;
-        pip install numexpr
-        pip install tables
+        zip $ZIP_FLAGS -r "$HOME/$VENV_FNAME" $SITE_PKG_DIR/
+        ls -l "$HOME/$VENV_FNAME"
+        echo "posting venv"
+        # silent, don't expose key
+        curl -s --form upload=@"$HOME/$VENV_FNAME" "$CACHE_FILE_STORE_URL/$VENV_FNAME"
     fi
-    pip $PIP_ARGS install sqlalchemy git+git://github.com/pydata/vbench.git;
-fi
 
-#build and install pandas
-python setup.py build_ext install
-
-#HACK: pandas is a statsmodels dependency
-# so we need to install it after pandas
-if [ x"$FULL_DEPS" == x"true" ]; then
-    pip install patsy
-    # pick recent 0.5dev dec/2012
-    pip install git+git://github.com/statsmodels/statsmodels@c9062e43b8a5f7385537ca95#egg=statsmodels
 fi;
 
-# make sure the desired locale is generated
-if [ x"$LOCALE_OVERRIDE" != x"" ]; then
-    # piggyback this build for plotting tests. oh boy.
-    pip install $PIP_ARGS --use-mirrors  matplotlib;
+#build and install pandas
+if [ x"$BUILD_CACHE_DIR" != x"" ]; then
+    scripts/use_build_cache.py -d
+    python setup.py install;
+else
+   python setup.py build_ext install
+fi
 
-    sudo locale-gen "$LOCALE_OVERRIDE"
+# package pandas build artifacts and send them home
+# that's everything the build cache (scripts/use_build_cache.py)
+# stored during the build (.so, pyx->.c and 2to3)
+if  (! $CACHE_FILE_AVAILABLE) ; then
+   echo "Posting artifacts"
+   strip  "$BUILD_CACHE_DIR/*" &> /dev/null
+   echo  "$BUILD_CACHE_DIR"
+   cd "$BUILD_CACHE_DIR"/
+   zip -r $ZIP_FLAGS "$HOME/$CYTHON_HASH".zip *
+   cd "$TRAVIS_BUILD_DIR"
+   pwd
+   zip "$HOME/$CYTHON_HASH".zip $(find pandas | grep -P '\.(pyx|pxd)$' | sed -r 's/.(pyx|pxd)$/.c/')
+
+   # silent, don't expose key
+   curl -s --form upload=@"$HOME/$CYTHON_HASH".zip "$CACHE_FILE_STORE_URL/$CYTHON_HASH.zip"
 fi
+
+true
diff --git a/scripts/use_build_cache.py b/scripts/use_build_cache.py
index 60833affd9373..361ac59e5e852 100755
--- a/scripts/use_build_cache.py
+++ b/scripts/use_build_cache.py
@@ -15,21 +15,29 @@
 Tested on releases back to 0.7.0.
 
 """
-import argparse
-argparser = argparse.ArgumentParser(description="""
-'Program description.
-""".strip())
 
-argparser.add_argument('-f', '--force-overwrite',
+try:
+    import argparse
+    argparser = argparse.ArgumentParser(description="""
+    'Program description.
+    """.strip())
+
+    argparser.add_argument('-f', '--force-overwrite',
                     default=False,
                    help='Setting this will overwrite any existing cache results for the current commit',
                    action='store_true')
-argparser.add_argument('-d', '--debug',
+    argparser.add_argument('-d', '--debug',
                     default=False,
                    help='Report cache hits/misses',
                    action='store_true')
 
-args = argparser.parse_args()
+    args = argparser.parse_args()
+except:
+    class Foo(object):
+        debug=False
+        force_overwrite=False
+
+    args = Foo() # for 2.6, no argparse
 
 #print args.accumulate(args.integers)
 
@@ -70,18 +78,28 @@
         import shutil
         import multiprocessing
         pyver = "%d.%d" % (sys.version_info[:2])
-        files = ["pandas"]
+        fileq = ["pandas"]
         to_process = dict()
-        orig_hashes= dict((f.split("-")[0],f)  for f in os.listdir(BUILD_CACHE_DIR)
-                      if "-" in f and f.endswith(pyver))
-        post_hashes= dict((f.split("-")[1],f)  for f in os.listdir(BUILD_CACHE_DIR)
-                      if "-" in f and f.endswith(pyver))
 
-        while files:
-            f = files.pop()
+        # retrieve the hashes existing in the cache
+        orig_hashes=dict()
+        post_hashes=dict()
+        for path,dirs,files in os.walk(os.path.join(BUILD_CACHE_DIR,'pandas')):
+            for f in files:
+                s=f.split(".py-")[-1]
+                try:
+                    prev_h,post_h,ver = s.split('-')
+                    if ver == pyver:
+                        orig_hashes[prev_h] = os.path.join(path,f)
+                        post_hashes[post_h] = os.path.join(path,f)
+                except:
+                    pass
+
+        while fileq:
+            f = fileq.pop()
 
             if os.path.isdir(f):
-                files.extend([os.path.join(f,x) for x in os.listdir(f)])
+                fileq.extend([os.path.join(f,x) for x in os.listdir(f)])
             else:
                 if not f.endswith(".py"):
                     continue
@@ -90,40 +108,54 @@
                         h = sha1(open(f,"rb").read()).hexdigest()
                     except IOError:
                         to_process[h] = f
-                    if h in orig_hashes and not BC_FORCE_OVERWRITE:
-                        src = os.path.join(BUILD_CACHE_DIR,orig_hashes[h])
-                        if BC_DEBUG:
-                            print("2to3 cache hit %s,%s" % (f,h))
-                        shutil.copyfile(src,f)
-                    elif h not in post_hashes:
-
-                        # we're not in a dev dir with already processed files
-                        if BC_DEBUG:
-                            print("2to3 cache miss %s,%s" % (f,h))
-                            print("2to3 will process " + f)
-                        to_process[h] = f
+                    else:
+                        if h in orig_hashes and not BC_FORCE_OVERWRITE:
+                            src = orig_hashes[h]
+                            if BC_DEBUG:
+                                print("2to3 cache hit %s,%s" % (f,h))
+                            shutil.copyfile(src,f)
+                        elif h not in post_hashes:
+                            # we're not in a dev dir with already processed files
+                            if BC_DEBUG:
+                                print("2to3 cache miss (will process) %s,%s" % (f,h))
+                            to_process[h] = f
 
         avail_fixes = set(refactor.get_fixers_from_package("lib2to3.fixes"))
         avail_fixes.discard('lib2to3.fixes.fix_next')
         t=refactor.RefactoringTool(avail_fixes)
-        print("Starting 2to3 refactoring...")
-        for f in to_process.values():
-            if BC_DEBUG:
-                print("2to3 on %s" % f)
-            try:
-                t.refactor([f],True)
-                post_h = sha1(open(f, "rb").read()).hexdigest()
-                cached_fname = f + "-" + post_h + "-" + pyver
+        if to_process:
+            print("Starting 2to3 refactoring...")
+            for orig_h,f in to_process.items():
                 if BC_DEBUG:
-                    print("cache put %s,%s in %s" % (f, h, cached_fname))
-                shutil.copyfile(f, os.path.join(BUILD_CACHE_DIR, cached_fname))
+                    print("2to3 on %s" % f)
+                try:
+                    t.refactor([f],True)
+                    post_h = sha1(open(f, "rb").read()).hexdigest()
+                    cached_fname = f + '-' + orig_h  + '-' + post_h + '-' + pyver
+                    path = os.path.join(BUILD_CACHE_DIR, cached_fname)
+                    pathdir =os.path.dirname(path)
+                    if BC_DEBUG:
+                        print("cache put %s in %s" % (f, path))
+                    try:
+                        os.makedirs(pathdir)
+                    except OSError as exc:
+                        import errno
+                        if exc.errno == errno.EEXIST and os.path.isdir(pathdir):
+                            pass
+                        else:
+                            raise
 
-            except:
-                pass
-        print("2to3 done refactoring.")
+                    shutil.copyfile(f, path)
+
+                except Exception as e:
+                    print("While processing %s 2to3 raised: %s" % (f,str(e)))
+
+                    pass
+            print("2to3 done refactoring.")
 
 except Exception as e:
-    print( "Exception: " + str(e))
+    if not isinstance(e,ZeroDivisionError):
+        print( "Exception: " + str(e))
     BUILD_CACHE_DIR = None
 
 class CompilationCacheMixin(object):