Following are test cases for failure modes in `rpmbuild`/`quilt` and `osc build`.

`ok`
----

* `rpmbuild` ✅, `osc build` ✅
* simple, normal package; control group

`empty_multibuild`
------------------

* `rpmbuild` ✅, `osc build` ✅
* empty multibuild flavors. It builds but can confuse 3rd party scripts.
* example: `SUSE:SLE-15-SP3:GA/pdsh`

`non_standard_macros`
---------------------

* `rpmbuild` ❌, `osc build` ✅
* contains for example `@``BUILD_FLAVOR@`
* example: most multibuild packages

`modifies_source_directory`
---------------------------

* `rpmbuild` ❌, `osc build` ✅
* writes to the source checkout which breaks rpmbuild when the sources are
read-only, e.g. when `rpmbuild` is sandboxed as it is, for example, in
`squilt`.
* example: `SUSE:SLE-15-SP7:Update/kernel-zfcpdump`

`exclusive_arch_no_rpmbuild`
----------------------------

* `rpmbuild` ❌, `osc build` ❌
* combination of broken rpmbuild + ExclusiveArch not native to the build host
* example: `openSUSE:Factory/arm-trusted-firmware`