double check the correctness of the build info for local build,

otherwise packages are stored incorrectly in the package cache
and that might cause problems later. Also refuse to build an
architecture locally that is not supported by the host architecture

osc/build.py

@@ -14,6 +14,7 @@ from tempfile import NamedTemporaryFile
 from osc.fetch import *
 from osc.core import get_buildinfo, store_read_apiurl, store_read_project, store_read_package, meta_exists, quote_plus, get_buildconfig
 import osc.conf
+import oscerr
 try:
     from xml.etree import cElementTree as ET
 except ImportError:
@@ -24,13 +25,15 @@ from conf import config
 change_personality = {
             'i686': 'linux32',
             'i586': 'linux32',
+            'i386': 'linux32',
             'ppc': 'powerpc32',
             's390': 's390',
         }
 
 can_also_build = { 
-             'x86_64': ['i686', 'i586'],
+             'x86_64': ['i686', 'i586', 'i386'],
              'i686': ['i586'],
+             'i386': ['i586'],
              'ppc64': ['ppc'],
              's390x': ['s390'],
             }
@@ -82,12 +85,23 @@ class Buildinfo:
 
         self.deps = []
         for node in root.findall('bdep'):
-            p = Pac(node.get('name'),
-                    node.get('version'),
-                    node.get('release'),
+            p_name = node.get('name')
+            p_arch = node.get('arch')
+            if not p_arch:
+                p_arch = self.buildarch
+            p_version = node.get('version')
+            p_release = node.get('release')
+
+            if not (p_name and p_arch and p_version and p_release):
+                raise oscerr.APIError(
+                    "buildinfo for package %s/%s/%s/%s is incomplete" % (p_name, p_arch, p_version, p_release))
+
+            p = Pac(p_name,
+                    p_version,
+                    p_release,
                     node.get('project'),
                     node.get('repository'),
-                    node.get('arch'),
+                    p_arch,
                     node.get('preinstall'),
                     node.get('runscripts'),
                     self.buildarch,       # buildarch is used only for the URL to access the full tree...
@@ -392,7 +406,9 @@ def main(opts, argv):
         # change personality, if needed
         if bi.buildarch in can_also_build.get(hostarch, []):
             cmd = change_personality[bi.buildarch] + ' ' + cmd
-
+        else:
+            print >>sys.stderr, 'Error: hostarch \'%s\' cannot build \'%s\'.' % (hostarch, bi.buildarch)
+            return 1
 
     print cmd
     rc = os.system(cmd)