Building packages with poudriere fails after `zfs upgrade`

From: Yasuhiro KIMURA <yasu_at_utahime.org> Date: Sun, 25 Oct 2020 14:52:05 +0900 (JST) · This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:25 UTC

Hello,

I tried `zfs upgrade zroot` on my 13-CURRENT r366977 host and after
that building packages with poudriere fails as following.

[00:04:55] [02] [00:00:00] Building security/libtasn1 | libtasn1-4.16.0
[00:05:10] [02] [00:00:15] Finished security/libtasn1 | libtasn1-4.16.0: Success
[00:05:10] [02] [00:00:00] Building devel/libunistring | libunistring-0.9.10_1
cannot rollback 'zroot/poudriere/jails/curamd64-original-ref/02': dataset is busy
[00:05:11] [02] [00:00:01] Error: Unable to rollback zroot/poudriere/jails/curamd64-original-ref/02 to prepkg
=>> Error: Unable to rollback zroot/poudriere/jails/curamd64-original-ref/02 to prepkg

How should I fix it?

Best Regards.

---
Yasuhiro KIMURA