Re: [libvirt PATCH] libxl: Fix build with recent Xen that introduces new disk backend type

On Mon, Aug 01, 2022 at 10:36:07AM +0100, Daniel P. Berrangé wrote: > Generally we want to see errors triggered from new enums arriving, > as it can be a sign that libvirt code needs a semantic change in > order to continue operating correctly. It isn't always correct > to assume that the 'default' case gives the correct behaviour. Isn't that the exact purpose of 'default' label? If use of 'default' means "any of the other 5 specific values, but lets save some characters to not name them explicitly", then IMHO better to name them explicitly... I can see a value of -Werror=switch-enum when adding new (internal) enum value, to find all the cases where code needs to be adjusted, but even then a grep is probably sufficient enough. On the other hand, if there are cases where indeed all the values of (internal API) enum needs to be handled explicitly, maybe simply omit 'default' label and use -Werror=switch? Anyway, if tracking all the enums values of all the used 3rd-party APIs is desirable (like, noticing when libxl adds new disk type), then it probably should be a separate CI job, not the default devel build. Otherwise breakages like this will happen from time to time, and will be annoyed for people on involved in specific code part at all. As a short term fix, maybe Xen's CI can build libvirt with -Wno-error=switch-enum?