Re: [libvirt PATCH v2 00/21] cleanup meson checks for runtime binaries

On Mon, 2021-04-19 at 19:14 +0200, Pavel Hrdina wrote: Overall I like this change, if nothing else because it finally cleans up the mess where some optional programs would be detected at build time while others would be detected at runtime, with no apparent reason for going one way rather than the other. The only concern I have, which is one I have expressed already in the past, is that it will now be harder for users and packagers alike to figure out that they don't have a certain optional program installed: AFAICT, after your patches the only way would be to try using each feature and look out for errors. Can we still check for the availability of these commands at build time and simply report their presence? I'm thinking of something like optional_runtime_programs = [ 'dmidecode', 'dnsmasq', ... ] which would be reported in the Meson summary as Optional runtime programs: dmidecode: YES dnsmasq: NO ... Then, for each of these commands, we'd also create a macro definition in meson-config.h like #define PROGRAM_DMIDECODE "dmidecode" #define PROGRAM_DNSMASQ "dnsmasq" ... and use those in the various C functions instead of the ad-hoc, private defines that are currently sprinkled throughout the code. Note that said macro would *not* be defined conditionally based on whether the optional program was found at build time: the intention is simply to have a single location where information about all these optional runtime programs are stored, instead of forcing users and packagers to go hunting for them across all of libvirt, potentially missing a bunch in the process. What do you think? -- Andrea Bolognani / Red Hat / Virtualization