RPM - rpmbuild tolerate binaries in noarch, README update

patch by Martin A. Langhoff; reviewed by Stefan Podkowinski for CASSANDRA-13433

redhat/README.md

@@ -7,25 +7,26 @@
 ### Step 1:
 - Build and copy sources to build tree:
 ```
-ant artifacts
+ant artifacts -Drelease=true
-cp build/apache-cassandra-*-src.tar.gz $RPM_BUILD_DIR/SOURCES/
 ```
 
 ### Step 2:
 - Since there is no version specified in the SPEC file, one needs to be passed at `rpmbuild` time (example with 4.0):
 ```
-rpmbuild --define="version 4.0" -ba redhat/cassandra.spec
+mkdir -p build/rpmbuild/{BUILD,RPMS,SPECS,SRPMS}
+rpmbuild --define="version 4.0" \
+    --define="revision $(date +"%Y%m%d")git$(git rev-parse --short HEAD)%{?dist}" \
+    --define "_topdir $(pwd)/build/rpmbuild" \
+    --define "_sourcedir $(pwd)/build" \
+    -ba redhat/cassandra.spec
 ```
 
+Use revision value in the example above for git based snapshots. Change to `--define="revision 1"` for non-snapshot releases.
+
 - RPM files can be found in their respective build tree directories:
 ```
-ls -l $RPM_BUILD_DIR/{SRPMS,RPMS}/
+ls -l build/rpmbuild/{SRPMS,RPMS}/
 ```
 
 ### Hint:
 - Don't build packages as root..
-```
-# this makes your RPM_BUILD_DIR = ~/rpmbuild
-mkdir -p ~/rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
-echo '%_topdir %(echo $HOME)/rpmbuild' > ~/.rpmmacros
-```

redhat/cassandra.spec

@@ -2,10 +2,13 @@
 # Turn off the brp-python-bytecompile script
 %global __os_install_post %(echo '%{__os_install_post}' | sed -e 's!/usr/lib[^[:space:]]*/brp-python-bytecompile[[:space:]].*$!!g')
 
+# rpmbuild should not barf when it spots we ship
+# binary executable files in our 'noarch' package
+%define _binaries_in_noarch_packages_terminate_build   0
+
 %global username cassandra
 
 %define relname apache-cassandra-%{version}
-%define revision 1
 
 Name:          cassandra
 Version:       %{version}