I'm trying to include mono in my image. I can successfully build the mono recipe by itself, but when I try to build my image it fails with the following error message:
Error:
 Problem: package test-sw-9.1.1b3-r0.aarch64 requires mono, but none of the providers can be installed
  - conflicting requests
  - nothing provides mono-gac needed by mono-5.12.0.226-r0.aarch64

This is a bit confusing since:
a) I can build mono by itself
b) the mono recipe should provide the mono-gac package

If I run 'bitbake -e mono | grep PACKAGES' I get the output:
PACKAGES="mono-dbg mono-doc mono-staticdev mono-locale mono-libs mono-dev  mono-config mono-binaries mono-libs-core  mono-libs-2.0 mono-libs-3.5 mono-libs-4.0 mono-libs-4.5  mono-api-4.5.1 mono-api-4.5.2 mono-api-4.6 mono-api-4.6.1 mono-api-4.6.2 mono-api-4.7  mono-libs-compat-2.0 mono-gac mono-configuration-crypto  mono-libs-monodoc mono-xbuild  mono-lldb  mono  mono-profiler "
PACKAGESPLITFUNCS="                 package_do_split_locales                 populate_packages"
PACKAGES_DYNAMIC="^mono-locale-.*"

So it would seem that bitbake agrees that mono provides mono-gac. The recipe for test-sw is a binary package, and depends on mono via:
RDEPENDS_${PN} = " \
  ...
  mono \
"
I am quite new to Yocto, so it could be something very basic that I am missing. I can actually build the image on my regular development machine, but when setting up the build on a second machine I started getting this error. I have verified that the new machine is using the same revisions of all layers, and there is nothing funny in the local.conf on my dev-machine. Any tips on what could be wrong would be most welcome!

I am using the Sumo release of Yocto.

Thanks,
Pelle