sqlsmith: nil pointer in tryBuildOpaque during ALTER TABLE DROP COLUMN CASCADE

[cockroach-teamcity]

roachtest.sqlsmith/setup=empty/setting=default failed with artifacts on release-23.1 @ 3551dc089ac3efcb3772df2109164dcb01e79d8f:

test artifacts and logs in: /artifacts/sqlsmith/setup=empty/setting=default/run_1
(sqlsmith.go:244).func3: error: pq: internal error: building declarative schema change targets for ALTER TABLE: runtime error: invalid memory address or nil pointer dereference
stmt:
ALTER TABLE defaultdb.public.tab454 DROP COLUMN "co l0_3" CASCADE;

Parameters: ROACHTEST_cloud=gce , ROACHTEST_cpu=4 , ROACHTEST_encrypted=false , ROACHTEST_ssd=0

Help

See: roachtest README

See: How To Investigate (internal)

Same failure on other branches

• roachtest: sqlsmith/setup=empty/setting=default failed #93689 roachtest: sqlsmith/setup=empty/setting=default failed [C-test-failure O-roachtest O-robot T-sql-queries T-sql-schema branch-master]

/cc @cockroachdb/sql-queries

This test on roachdash | Improve this report!

Jira issue: CRDB-26058

[michae2]

Reduced to:

SET sql_safe_updates = off;

CREATE TABLE tab26 (
  "c
    ol0_2"      BYTES,
  "co l0_3"      TIMETZ,
  "col😏0%p_4" REGROLE,
  col0_5         TIMESTAMPTZ,
  "cOl0_7"       GEOGRAPHY[],
  "c'oL0_8"      BOOL,
  col0_12        CHAR,
  "-col0_14"     DATE NOT NULL,
  UNIQUE ("co l0_3" ASC, lower(CAST("co l0_3" AS STRING)) ASC)
);

ALTER TABLE tab26 RENAME TO tab454;

ALTER TABLE tab454 DROP COLUMN "co l0_3" CASCADE;

[michae2]

Further reduced to:

SET sql_safe_updates = off;
CREATE TABLE t (
  col TIMETZ,
  UNIQUE (col, CAST(col AS STRING))
);
ALTER TABLE t DROP COLUMN col CASCADE;

Error is:

> ALTER TABLE t DROP COLUMN col CASCADE;
ERROR: internal error: building declarative schema change targets for ALTER TABLE: runtime error: invalid memory address or nil pointer dereference
SQLSTATE: XX000
DETAIL: stack trace:
github.com/cockroachdb/cockroach/pkg/util/errorutil/catch.go:29: ShouldCatch()
github.com/cockroachdb/cockroach/pkg/sql/opt/optbuilder/builder.go:209: func1()
GOROOT/src/runtime/panic.go:884: gopanic()
github.com/cockroachdb/cockroach/pkg/sql/opt/optbuilder/opaque.go:72: tryBuildOpaque()
github.com/cockroachdb/cockroach/pkg/sql/opt/optbuilder/builder.go:425: buildStmt()
github.com/cockroachdb/cockroach/pkg/sql/opt/optbuilder/builder.go:269: buildStmtAtRoot()
github.com/cockroachdb/cockroach/pkg/sql/opt/optbuilder/builder.go:243: Build()
github.com/cockroachdb/cockroach/pkg/sql/plan_opt.go:573: buildExecMemo()
github.com/cockroachdb/cockroach/pkg/sql/plan_opt.go:237: makeOptimizerPlan()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor_exec.go:1640: makeExecPlan()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor_exec.go:1246: dispatchToExecutionEngine()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor_exec.go:770: execStmtInOpenState()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor_exec.go:137: func1()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor_exec.go:2660: execWithProfiling()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor_exec.go:136: execStmt()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor.go:2117: func1()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor.go:2122: execCmd()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor.go:2038: run()
github.com/cockroachdb/cockroach/pkg/sql/conn_executor.go:867: ServeConn()
github.com/cockroachdb/cockroach/pkg/sql/pgwire/conn.go:738: func1()
GOROOT/src/runtime/asm_amd64.s:1594: goexit()

[ajwerner]

@Xiang-Gu can you have a look?