Cannot install a version of GDAL via Anaconda that permits reading BigTIFFs

Issues:

1. The Anaconda default gdal may be built without BigTIFF support. If I create a non conda-forge env, i.e conda create -n testgdal gdal I can reproduce the md['DMD_CREATIONOPTIONLIST'].find('BigTIFF') == -1 no BigTIFF issue.
2. There seems to be an incompatibility between the latest version of conda and vs2015_runtime and conda-forge. I updated my conda to 4.5.9 to match yours and vs2015_runtime (the Visual C++ runtime for applications compiled with MS Visual Studio) was upgraded from 14 to 15. If I then create a conda env with gdal from the conda-forge channel, I get the same ImportError: DLL load failed.

Fix:

If I create a conda-forge env and specify vs2015_runtime=14, everything works:

conda create -n testgdal -c conda-forge gdal vs2015_runtime=14
activate testgdal 

(testgdal)  python
Python 3.6.6 | packaged by conda-forge | (default, Jul 26 2018, 11:48:23) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from osgeo import gdal
>>> md = gdal.GetDriverByName('GTiff').GetMetadata()
>>> md['DMD_CREATIONOPTIONLIST'].find('BigTIFF')
2953

Here's the discussion on the conda-forge lists with the background on the DLL load error. I encountered the same issue where it stopped working after doing a conda update gdal, and pinning vs2015_runtime to 14 works as noted.