buildman: Allow conflicting tags to avoid spurious errors

Conflicting tags can prevent buildman from building two series which exist
one after the other in a branch. There is no reason not to allow this sort
of workflow with buildman, so ignore conflicting tags in buildman.

Change-Id: I2231d04d8684fe0f8fe77f8ea107e5899a3da5e8
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index 8d7b9b5..3e5f56c 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -137,6 +137,11 @@
     upstream_commit = gitutil.GetUpstream(options.git_dir, options.branch)
     series = patchstream.GetMetaDataForList(upstream_commit, options.git_dir,
             1)
+    # Conflicting tags are not a problem for buildman, since it does not use
+    # them. For example, Series-version is not useful for buildman. On the
+    # other hand conflicting tags will cause an error. So allow later tags
+    # to overwrite earlier ones.
+    series.allow_overwrite = True
     series = patchstream.GetMetaDataForList(range_expr, options.git_dir, None,
             series)