Both appstream-glib and gnome-software have optional dependencies on RPM, and the default values of enable-rpm option are true. This is fine for distributions using RPM as their system package managers, but it causes meson to fail on non-RPM distributions.

*** Configuring appstream-glib *** [1/1]
The Meson build system
Version: 0.40.1
...
Meson encountered an error in file meson.build, line 73, column 4:
Native dependency 'rpm' not found
*** Error during phase configure of appstream-glib: ########## Error running meson --prefix ... *** [1/1]

I know it is possible to avoid the error by setting module_mesonargs['appstream-glib'] = '-Denable-rpm=false' in jhbuildrc, but asking all users of non-RPM distributions to manually add a line in jhbuildrc doesn't seem to be a correct solution. We have condition set support in jhbuild, but we don't have an 'rpm' condition that can be used to conditionally add '-Denable-rpm=false' in modulesets.