Enhancements:
-------------
* implement "--exclusive-config-file" CLI flag to render & build. This file
bypasses detection of config files in $HOME and cwd, but respects any config
files in recipe folders. #2661
* Activate output scripts in meta.yaml ( #2667 ), but only when:
* output has a build/script entry
* output uses ``{{ compiler() }}`` jinja2 function in its requirements AND output extension is either .sh or .bat
* output has ``build/activate_in_script`` key in meta.yaml set to a truthy value AND output extension is either .sh or .bat
Bug fixes:
----------
* fix AttributeError in overlinking check #2650 #2651
* reorder mmap operations to fix problem with WSL #2655
* fix numpy detection as "used" variable when using pin_compatible jinja2 #2659
* silence conda KeyError warnings when indexing legacy packages that don't have newer metadata files #2656
* replace "which" with "type -P" in conda-build's internal recipe. This avoids issues on PowerPC and with long paths. #2664
* Error out when version computation fails in conda-build's setup.py. This will
help prevent conda-build packages going out without valid internal versions
being recorded (for example, when git is not installed on a build worker).
#2665
* ignore tarcheck errors for files in the info folder that don't appear in info/files file. Fixes inclusion of arbitrarily named readme files. #2668
* clean up host prefix in between skeletons when using pypi's --recursive mode. Conda otherwise throws errors on the 2nd recipe. #2669