following packages have unmet dependencies: sbuild-build-depends-main-dummy

Can anyone can give me some hints, thanks.

When I have a look at https://launchpad.net/~lee-emqx/+archive/ubuntu/ppa I can read
- build failure 22 hours ago
- package uploaded 21 hours ago

Could you please verify that you still have issues?

Could you please give a link to your build configuration file?

Thank you

Thanks for your reply.
I have verified that, issues still there.
But I donot understand which configuration file do you need?
nanomq_0.6.8.tar.xz
nanomq_0.6.8_source.build
nanomq_0.6.8_source.buildinfo
UbuntuCodeofConduct-2.0.txt
nanomq_0.6.8_source.changes
nanomq_0.6.8_source.ppa.upload
nanomq_0.6.8.dsc
debian/
|-- README
|-- README.Debian
|-- README.source
|-- changelog
|-- control
|-- copyright
|-- files
|-- nanomq-docs.docs
|-- rules
`-- source
    `-- format

sbuild-build-depends-main-dummy is a "fake" package that is created during building to cater for the build dependencies.

From your build log:
The following packages have unmet dependencies:
 sbuild-build-depends-main-dummy : Depends: debhelper-compat (= 13)

This is in line with your control file which states:
Build-Depends: debhelper-compat (= 13)

debhelper-compat (= 13) is provided in focal only by the debhelper package from focal-backports, but not in the "standard" focal repository.

Configure your PPA by adding a dependency on backports

Thanks for your help, Manfred!