add new stage option for the build script

(minor code improvement for handing over release number)

NEWS

@@ -1,6 +1,9 @@
 0.173.0
   - add showlinked command to show all references of packages linking to a given one
   - add build --shell-after-build flag. It can also be set via .oscrc.
+  - add build --stage flag. Useful for example for fixing file lists and just
+    running the install section to see the result of it (use --stage=i=).
+    Check the help for more details.
 
 0.172.0
   - support --lastsucceeded/--last-succeeded in "osc buildlog", "osc

osc/build.py

@@ -936,7 +936,12 @@ def main(apiurl, opts, argv):
         bi.release = opts.release
 
     if bi.release:
-        buildargs.append('--release=%s' % bi.release)
+        buildargs.append('--release')
+        buildargs.append(bi.release)
+
+    if opts.stage:
+        buildargs.append('--stage')
+        buildargs.append(opts.stage)
 
     if opts.build_opt:
         buildargs += opts.build_opt

osc/commandline.py

@@ -6478,6 +6478,11 @@ Please submit there instead, or use --nodevelproject to force direct submission.
                   'unprivileged "abuild" user or use "caller" to use the current user uid:gid')
     @cmdln.option('--local-package', action='store_true',
                   help='build a package which does not exist on the server')
+    @cmdln.option('--stage', metavar='STAGE',
+                  help='runs a specific stage, default is "a" for all. Append a trailing "="'
+                       'to only run the specified stage. Append a trailing "+" to run'
+                       'the specified stage and all stages coming after it. With no'
+                       'suffix, stages up to and included the specified stage are run.')
     @cmdln.option('--linksources', action='store_true',
                   help='use hard links instead of a deep copied source')
     @cmdln.option('--vm-memory', metavar='MEMORY',