From Fedora Project Wiki

Proposal: It is important to carefully handle the !BuildRoot during %install, to ensure that it is created fresh. I propose that the following be added to the Packaging/Guidelines (as a subsection to BuildRoot ):

Prepping BuildRoot For %install

It is important to properly prepare the !BuildRoot in the %install section of your package before it is used. Every Fedora package MUST have an %install section that begins with either:

%install
rm -rf %{buildroot}

or

%install
rm -rf $RPM_BUILD_ROOT

This is to ensure that the !BuildRoot will be created fresh during the %install section.


Also, the following will be added to Packaging/ReviewGuidelines:

- MUST: At the beginning of %install, each package MUST run rm -rf %{buildroot} (Packaging/Guidelines#Using_.25.7Bbuildroot.7D_and_.25.7Boptflags.7D_vs_.24RPM_BUILD_ROOT_and_.24RPM_OPT_FLAGS ). See Packaging/Guidelines#Prepping_BuildRoot_For_.25install for details.