Some ebuilds allow a reduced number of components to be built by setting ebuild specific environment vars, Alsa is one such ebuild. It would also be nice if ebuilds that had this functionality could inform the user just prior to commencing the emerge, and pause for a few (5) seconds prior to starting the emerge. eg: psuedo-code if no ebuild specific environment vars then beep cat <<EOT This ebuild has the ability to compile a reduced number of components To specify the components to build do the following: export EBUILD_ENVIRONMENT_VAR=component; emerge package The components that this ebuild can process are: component1 component2 This ebuild will now pause for 5 seconds. If you wish to set the environment variable press CTRL+C to stop the process, otherwise all components will be built EOT sleep 5 fi rest of ebuild as per normal.
arcady, what's this about alsa being thinner?
Seemant: alsa-driver allows specifying which drivers to build by setting ALSA_CARDS environment variable. This can significantly reduce compile time. ;^) This is documented at the very top of the ebuild file. I used similar approach is used to compile WindowMaker with XKB mode lock support. The idea comes from FreeBSD's ports. Troy: I'd agree that this needs to be communicated at the build time. I'm opposed to the idea of beeping and halting for 5 seconds, at least for alsa-driver. This is not really important to pause; it's sort of easter egg kinda stuff. IMO, this should be handled by the ebuild maintainer on a per-package basis. I'll insert an einfo somewhere to print a message, documenting the feature.
My main reason for posting this bug was because of bug #3575 that proposes a discreet ebuild for a browser only Mozilla. Using the env vars seemed like a neat solution that would not require a complete new ebuild. I figured a short pause would give people time to back out, otherwise everything just goes as normal and they are none the wiser. What's 5 seconds to a 2 or 3 hour build of say Mozilla :) ? I'll leave the implementation up to the experts.
I wouldn't mind if emerge -s reported that the ebuild takes environment variables, but I don't like the idea of pausing an ebuild. I'm pretty sure that subpackages are still in the works, and this is a good case for them.
I'm going to close this one. The Alsa installation manual (part of the Desktop configuration guide) now mentions the ALSA_CARDS build-time environment variable. As the maintainer of the alsa package I choose not to include the beep + sleep 5 in this particular case. I think that there is *very* little harm in having everybody compile all alsa drivers, not enough for bugging everybody with a beep and pause. ;^)
