1.21.8

Bug fixes:

• Fix --source argument to build - was building when should only download source. #1152
• Don't try to create work folder when it exists (but is empty) #1153
• Fix a logic error with need_source_download not existing #1148

New Things:

• Don't exit on compileall failure #1146
• Add CONDA_BUILD_RENDERING environment variable that is set during recipe rendering #1154
• Change pyc compilation to only affect files that would be packaged (not all of site-packages). Compile pyc files on py3. #1155
• Rename load_setuptools to load_setup_py_data (keep load_setuptools for compat; but show warning) #1156
• Test that condarc channels are respected in build #1157

Contributors:

• @daler
• @minrk
• @msarahan