$RPM_SOURCE_DIR or %{_sourcedir}

Packages which use files itemized as Source# files, must refer to those files by their Source# macro name, and must not use $RPM_SOURCE_DIR or %{sourcedir} to refer to those files.

This is done to ensure that Fedora SRPMS are properly generated. If a Source# item is renamed, a spec which refers to its old name may succeed locally (because the file is still in %{_sourcedir} along with the new file), but the proper file will not be included in the SRPM.

Incorrect Use:

Source: php.conf
Source: php.ini
Source: macros.php

...

install -m 644 $RPM_SOURCE_DIR/php.conf $RPM_BUILD_ROOT/etc/httpd/conf.d
sed -e "s/@PHP_APIVER@/%{apiver}/;s/@PHP_ZENDVER@/%{zendver}/;s/@PHP_PDOVER@/%{pdover}/" \
    < $RPM_SOURCE_DIR/macros.php > macros.php

Correct Use:

Source1: php.conf
Source2: php.ini
Source3: macros.php

...

install -m 644 %{SOURCE1} $RPM_BUILD_ROOT/etc/httpd/conf.d
sed -e "s/@PHP_APIVER@/%{apiver}/;s/@PHP_ZENDVER@/%{zendver}/;s/@PHP_PDOVER@/%{pdover}/" \
    < %{SOURCE3} > macros.php

Exceptions

When there is an available list of supplementary source files, it is permissible to use this list in conjunction with %{sourcedir} to simplify operations on those supplementary source files.

An example of this from the kde-l10n package:

for i in $(cat %{SOURCE1000}) ; do
  echo $i | grep -v '^#' && \
  bzip2 -dc %{_sourcedir}/%{name}-$i-%{version}.tar.bz2 | tar -xf -
done

where Source1000: subdirs-kde-l10n is a list provided by upstream of all the languages supported, and there are ~50 SourceN: tags, which can vary from version from version, but match the languages listed in Source1000, for the tarballs provided by upstream.