[Bug 35540] Using alsamixer/amixer after selecting a non-default sound card (System> Preferences> Sound> Default sound card) results in errors

[Daniel T. Chen]

Public bug report changed:
https://launchpad.net/malone/bugs/35540

Description changed to:
    debian/patches/23_default_soundcard_selector.patch needs to be
    modified to set defaults.ctl.card in addition to defaults.pcm.card
    in ~/.asoundrc.asoundconf after the user selects a non-default sound
    card using the System> Preferences> Sound> Default sound card menu.
    Otherwise, the following error occurs when using alsamixer (or
    amixer) from the command line:

    ALSA lib confmisc.c:1107:(snd_func_refer) Unable to find definition 'defaults.ctl.card'
    ALSA lib conf.c:3493:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
    ALSA lib confmisc.c:242:(snd_func_getenv) error evaluating default
    ALSA lib conf.c:3493:(_snd_config_evaluate) function snd_func_getenv returned error: No such file or directory
    ALSA lib conf.c:3962:(snd_config_expand) Evaluate error: No such file or directory
    ALSA lib control.c:817:(snd_ctl_open_noupdate) Invalid CTL default
    amixer: Mixer attach default error: No such file or directory