tdowty@ubuntu:~/amd/poky-amd-kirkstone/build-v3000-kirkstone$ bitbake -e secure-core-image
Loading cache: 100% |                                                                                                                                                                       | ETA:  --:--:--
Loaded 0 entries from dependency cache.
Parsing recipes: 100% |######################################################################################################################################################################| Time: 0:00:18
Parsing of 2568 .bb files complete (0 cached, 2568 parsed). 4058 targets, 90 skipped, 0 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies
ERROR: Nothing RPROVIDES 'dnf' (but /home/tdowty/amd/poky-amd-kirkstone/meta-secure-core/meta/recipes-core/images/secure-core-image.bb RDEPENDS on or otherwise requires it)
dnf was skipped: Recipe will be skipped because: does not build without package_rpm in PACKAGE_CLASSES due disabled rpm support in libsolv
NOTE: Runtime target 'dnf' is unbuildable, removing...
Missing or unbuildable dependency chain was: ['dnf']
ERROR: Required build target 'secure-core-image' has no buildable providers.
Missing or unbuildable dependency chain was: ['secure-core-image', 'dnf']

Summary: There were 2 ERROR messages, returning a non-zero exit code.