Hi,

During a rebuild of all packages in sid, your package failed to build
on arm64 (I don't know if it also fails on amd64).

Relevant part (hopefully):
http://qa-logs.debian.net/2020/12/05/openstructure_2.2.0-1_unstable.log

A list of current common problems and possible solutions is available at
http://wiki.debian.org/qa.debian.org/FTBFS . You're welcome to contribute!

If you reassign this bug to another package, please marking it as 'affects'-ing
this package. See https://www.debian.org/Bugs/server-control#affects

If you fail to reproduce this, please provide a build log and diff it with me
so that we can identify if something relevant changed in the meantime.

About the archive rebuild: The rebuild was done on EC2 VM instances from
Amazon Web Services, using a clean, minimal and up-to-date chroot. Every
failed build was retried once to eliminate random failures.