diff --git a/roles/git/make_checkout_seed/files/alternative_arch_report.py b/roles/git/make_checkout_seed/files/alternative_arch_report.py
new file mode 100644
index 0000000000..a060cbeee8
--- /dev/null
+++ b/roles/git/make_checkout_seed/files/alternative_arch_report.py
@@ -0,0 +1,143 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+"""
+This script does a few things:
+- It iterates over all the spec files found in the given directory
+- For each of these files it finds all the lines starting with `ExclusiveArch`
+  or `ExcludesArch`
+- It thus builds a dictionnary of filenames -> list of lines of interest
+- If it ran before and this ``RESULTS`` file is found, it compares the
+  current list of packages with the old one and report:
+    - Packages that are now restricting their build arch where they weren't
+    - Packages that changes their build arch constraints
+    - Packages that no longer restrict their build arch
+- Finally it prints anyway the entire list of packages restricting their
+  build arch and save it in JSON in ``RESULTS`` (cf line 33)
+
+To run it:
+
+  python alternative_arch_report.py /srv/git_seed/rpm-specs > output
+
+"""
+
+
+import itertools
+import json
+import sys
+import os
+
+from multiprocessing import Pool, Manager
+
+
+RESULTS = '/srv/cache/lookaside/excluding_arches.json'
+
+
+def parse_folder(arg):
+    """ This function does something important in parallel but where we
+    want to centralize the output, thus using the queue
+    """
+    filename, foldername, myq = arg
+
+    with open(os.path.join(foldername, filename)) as stream:
+        data = stream.read()
+
+    cnt = data.count('ExclusiveArch') + data.count('ExcludesArch')
+
+    lines = []
+    if cnt > 0:
+        data = data.split('\n')
+        for line in data:
+            if line.startswith(('ExclusiveArch', 'ExcludesArch')):
+                lines.append(line)
+            if len(lines) == cnt:
+                break
+
+    if lines:
+        name = filename.replace('.spec', '')
+        myq.put((name, lines))
+        myq.task_done()
+
+def main():
+    ''' For a specified folder, check all the sub-folder for spec files
+    and report if any of them is excluding some arches.
+    '''
+    if len(sys.argv) == 1:
+        print 'alternative_arch_report.py /path/to/folder/with/spec'
+        return 1
+
+    foldername = sys.argv[1]
+    if not os.path.isdir(foldername):
+        print '%s must be a folder' % foldername
+        return 2
+
+    files = os.listdir(foldername)
+    m = Manager()
+    q = m.Queue()
+    p = Pool(5)
+    p.map(parse_folder, itertools.product(files, [foldername], [q]))
+
+    excluding_arches = {}
+    while q.qsize():
+        item = q.get()
+        excluding_arches[item[0]] = item[1]
+    q.join()
+
+    previous_data = None
+    if os.path.exists(RESULTS):
+        with open(RESULTS) as stream:
+            previous_data = json.load(stream)
+
+    new = {}
+    changed = {}
+    removed = []
+    if previous_data:
+        prev_pkgs = set(previous_data)
+        cur_pkgs = set(excluding_arches)
+        new = dict((pkg, excluding_arches[pkg]) for pkg in cur_pkgs - prev_pkgs)
+        removed = prev_pkgs - cur_pkgs
+        changed = [pkg for pkg in cur_pkgs.intersection(prev_pkgs)
+            if sorted(previous_data[pkg]) != sorted(excluding_arches[pkg])]
+
+    def _fmt_output(pkg, data):
+        print ' - %s\n      %s' % (
+                pkg,
+                '\n      '.join(data[pkg])
+            )
+
+    if new:
+        print 'New package excluding arches (%s)' % len(new)
+        print '============================\n'
+        for pkg in sorted(new):
+            _fmt_output(pkg, excluding_arches)
+        print '\n'
+
+    if changed:
+        print 'Package that edited their arches constraints (%s)' % len(changed)
+        print '=============================================\n'
+        for pkg in sorted(changed):
+            print ' - %s' % pkg
+            print '   was   %s' % '\n         '.join(previous_data[pkg])
+            print '    is   %s' % '\n         '.join(excluding_arches[pkg])
+            print '\n'
+
+    if removed:
+        print 'Package no longer excluding arches (%s)'  % len(removed)
+        print '==================================\n'
+        for pkg in sorted(removed):
+            print ' - %s' % pkg
+            print '\n'
+
+    print 'List of packages currently excluding arches (%s)' % len(excluding_arches)
+    print '===========================================\n'
+    for pkg in sorted(excluding_arches):
+        _fmt_output(pkg, excluding_arches)
+
+    with open(RESULTS, 'w') as stream:
+        json.dump(excluding_arches, stream)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/roles/git/make_checkout_seed/files/make-git-checkout-seed.sh b/roles/git/make_checkout_seed/files/make-git-checkout-seed.sh
index 074a8ff6b2..d1bbf1f19f 100644
--- a/roles/git/make_checkout_seed/files/make-git-checkout-seed.sh
+++ b/roles/git/make_checkout_seed/files/make-git-checkout-seed.sh
@@ -71,3 +71,6 @@ mv $OUTPUT_DIR/.git-seed-$DATE.tar.xz $OUTPUT_DIR/git-seed-$DATE.tar.xz
 mv $OUTPUT_DIR/.rpm-specs-$DATE.tar.xz $OUTPUT_DIR/rpm-specs-$DATE.tar.xz
 ln -s git-seed-$DATE.tar.xz $OUTPUT_DIR/git-seed-latest.tar.xz
 ln -s rpm-specs-$DATE.tar.xz $OUTPUT_DIR/rpm-specs-latest.tar.xz
+
+python2 /usr/local/bin/alternative_arch_report.py /srv/git_seed/rpm-specs/ | \
+    mail -s "[Report] Packages Restricting Arches" pingou@fedoraproject.org
diff --git a/roles/git/make_checkout_seed/tasks/main.yml b/roles/git/make_checkout_seed/tasks/main.yml
index 8c72a88f01..c387ed3a62 100644
--- a/roles/git/make_checkout_seed/tasks/main.yml
+++ b/roles/git/make_checkout_seed/tasks/main.yml
@@ -9,6 +9,10 @@
   copy: src=make-git-checkout-seed.sh dest=/usr/local/bin/make-git-checkout-seed.sh mode=0755
   when: env != 'staging'
 
+- name: install the alternative arch report script
+  copy: src=alternative_arch_report.py dest=/usr/local/bin/alternative_arch_report.py mode=0755
+  when: env != 'staging'
+
 - name: install cron job.
   cron: >
     name="make-git-checkout-seed" cron_file="ansible-make-git-checkout-seed"