Alexander Sosna <alexander(dot)sosna(at)credativ(dot)de> writes:
> I can reproduce a segmentation fault when creating a BRIN concurrently
> with set pages_per_range and autosummarize.
I wonder if this isn't the same issue reported in
https://www.postgresql.org/message-id/flat/20170524063323.29941.46339%40wrigleys.postgresql.org
Could you try the patch suggested there?
regards, tom lane