Update travis data download to zenodo, update conda macos CFLAGS_HOST…

… variable (#308)

* update conda macos CFLAGS_HOST variable to address older installs of sdk

* update travis data download from zenodo

.travis.yml

@@ -19,8 +19,8 @@ addons:
 
 install:
   # Fetch Icepack-specific dataset
-  - "wget ftp://ftp.cgd.ucar.edu/archive/Model-Data/CICE/Icepack_data.tar.gz &&
-    tar xvfz Icepack_data.tar.gz -C ~"
+  - "wget https://zenodo.org/record/3728287/files/Icepack_data-20200326.tar.gz &&
+    tar xvfz Icepack_data-20200326.tar.gz -C ~"
 
   # Mirror entire data folder
   #- "lftp ftp://anonymous:travis@travis-ci.org@ftp.cgd.ucar.edu 

configuration/scripts/machines/Macros.conda_macos

@@ -27,7 +27,12 @@ FC := $(SFC)
 LD := $(FC)
 
 # Location of the system C header files (required on recent macOS to compile makdep)
-CFLAGS_HOST = -isysroot$(shell xcrun --show-sdk-path)
+SDKPATH = $(shell xcrun --show-sdk-path)
+ifeq ($(strip $(SDKPATH)),)
+  CFLAGS_HOST := 
+else
+  CFLAGS_HOST = -isysroot $(SDKPATH)
+endif
 
 # Necessary flag to compile with OpenMP support
 ifeq ($(ICE_THREADED), true)

doc/source/user_guide/ug_running.rst

@@ -524,7 +524,7 @@ If you prefer that some or all of the Icepack directories be located somewhere e
 
 Note: if you wish, you can also create a complete machine port for your computer by leveraging the conda configuration as a starting point. See :ref:`porting`.
 
-Next, create the "icepack" conda environment from the ``environment.yml`` file:
+Next, create the "icepack" conda environment from the ``environment.yml`` file in the Icepack source code repository.  You will need to clone Icepack to run the following command:
 
 .. code-block:: bash