$ pip install reportlab
After running this command
clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future] clang: note: this will be a hard error (cannot be downgraded to a warning) in the future error: command 'cc' failed with exit status 1
I encountered this error.
It seems to occur during the installation of a dependency package (pillow?).
Fix 'clang: unknown argument' error after updating to Xcode 5.1
http://kaspermunck.github.io/2014/03/fixing-clang-error/
Referring to this page
ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future pip install reportlab