Add Environment Variables When You Encounter the Error "pip install pillow → error: command 'cc' failed with exit status 1"

When running pip install pillow, you might encounter the following error:

cc -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -mno-fused-madd -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -arch x86_64 -arch i386 -pipe -DHAVE_LIBJPEG -DHAVE_LIBZ -DHAVE_LIBTIFF -I/System/Library/Frameworks/Tcl.framework/Versions/8.5/Headers -I/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -I/opt/X11/include/freetype2 -I/private/tmp/pip_build_root/pillow/libImaging -I/System/Library/Frameworks/Python.framework/Versions/2.7/include -I/opt/X11/include -I/usr/local/include -I/usr/include -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c _imaging.c -o build/temp.macosx-10.9-intel-2.7/_imaging.o

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

In such a case, you can resolve the issue by executing the following commands:

(sudo su -)
export CFLAGS=-Qunused-arguments
export CPPFLAGS=-Qunused-arguments
pip install pillow

Reference: clang error: unknown argument: '-mno-fused-madd' (python package installation failure) - Stack Overflow