The test failed on branch=release-21.2, cloud=gce:
test artifacts and logs in: /home/agent/work/.go/src/github.com/cockroachdb/cockroach/artifacts/sqlsmith/setup=rand-tables/setting=default/run_1
	sqlsmith.go:223,sqlsmith.go:256,test_runner.go:777: error: pq: internal error: failed to construct index entries during backfill: Non-nullable column "table2:col2_10" with no value! Index scanned was "primary" with the index key columns (col2_3,col2_5,col2_4,col2_1,col2_2) and the values ('BOX(-0.4617848234054447 0.9693919887931086,1.2249223709052481 1.8834189112191637)',997066855,e'\x7f',1949454573,492325614)
		stmt:
		ALTER TABLE defaultdb.public.table2 ALTER PRIMARY KEY USING COLUMNS (col2_4, col2_1);