Please answer these questions before submitting your issue. Thanks!

1. What did you do?

First set up a TiDB with alter-primary-key = true.

Create a table:

create table test.a (a int primary key, b int unique);
insert into test.a values (42, 42);

Run backup

bin/br backup table --db test -t a -s 'local:///tmp/brapk'

Drop the table

drop table test.a;

Restore

bin/br restore table --db test -t a -s 'local:///tmp/brapk'

2. What did you expect to see?

Restore success and checksum pass

3. What did you see instead?

An "ranges overlapped" error

[2020/03/27 13:38:22.085 +00:00] [ERROR] [restore.go:225] ["split regions failed"] [error="ranges overlapped: [74800000000000003b5f69800000000000000100 74800000000000003b5f698000000000000001fb],

4. What version of BR and TiDB/TiKV/PD are you using?

Cluster: 4.0
BR: master