Emit explicit error message if user tries to build RPM as root

mysql.spec

@@ -1,6 +1,6 @@
 Name: mysql
 Version: 5.1.42
-Release: 5%{?dist}
+Release: 6%{?dist}
 Summary: MySQL client programs and shared libraries
 Group: Applications/Databases
 URL: http://www.mysql.com
@@ -189,6 +189,17 @@ autoconf
 autoheader
 
 %build
+
+# fail quickly and obviously if user tries to build as root
+%if %runselftest
+	if [ x"`id -u`" = x0 ]; then
+		echo "mysql's regression tests fail if run as root."
+		echo "If you really need to build the RPM as root, use"
+		echo "--define='runselftest 0' to skip the regression tests."
+		exit 1
+	fi
+%endif
+
 CFLAGS="%{optflags} -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE"
 # MySQL 4.1.10 definitely doesn't work under strict aliasing; also,
 # gcc 4.1 breaks MySQL 5.0.16 without -fwrapv
@@ -655,6 +666,10 @@ fi
 %{_mandir}/man1/mysql_client_test.1*
 
 %changelog
+* Tue Jan 26 2010 Tom Lane <tgl@redhat.com> 5.1.42-6
+- Emit explicit error message if user tries to build RPM as root
+Related: #558915
+
 * Wed Jan 20 2010 Tom Lane <tgl@redhat.com> 5.1.42-5
 - Correct Source0: tag and comment to reflect how to get the tarball