我继承了与MIDI设备通信的软件，因此ALSA和pulseaudio都参与其中。在从头开始构建的 BI 系统中，存在以下错误：
No protocol specified
xcb_connection_has_error() returned true
并在系统日志中：
Aug 24 17:43:29 debianl016 pulseaudio[2206]: [pulseaudio] client-conf-x11.c: xcb_connection_has_error() returned true
Aug 24 17:43:29 debianl016 pulseaudio[2204]: [pulseaudio] client-conf-x11.c: xcb_connection_has_error() returned true
Aug 24 17:43:29 debianl016 rtkit-daemon[1216]: Successfully made thread 2215 of process 2215 (/usr/bin/pulseaudio) owned by '2003' high priority at nice level -11.
Aug 24 17:43:29 debianl016 rtkit-daemon[1216]: Supervising 1 threads of 1 processes of 1 users.
Aug 24 17:43:29 debianl016 pulseaudio[2215]: [pulseaudio] main.c: Daemon startup without any loaded modules, refusing to work.
Aug 24 17:43:29 debianl016 pulseaudio[2206]: [pulseaudio] main.c: Daemon startup failed.
Aug 24 17:43:29 debianl016 rtkit-daemon[1216]: Successfully made thread 2217 of process 2217 (/usr/bin/pulseaudio) owned by '2003' high priority at nice level -11.
Aug 24 17:43:29 debianl016 rtkit-daemon[1216]: Supervising 1 threads of 1 processes of 1 users.
Aug 24 17:43:29 debianl016 pulseaudio[2217]: [pulseaudio] main.c: Daemon startup without any loaded modules, refusing to work.
Aug 24 17:43:29 debianl016 pulseaudio[2204]: [pulseaudio] main.c: Daemon startup failed.
Aug 24 17:43:29 debianl016 kernel: [ 338.958104] usb 1-2.4: USB disconnect, device number 9
Aug 24 17:43:29 debianl016 kernel: [ 339.256760] usb 1-2.4: new full-speed USB device number 12 using xhci_hcd
Aug 24 17:43:30 debianl016 kernel: [ 339.447919] usb 1-2.4: New USB device found, idVendor=04d8, idProduct=0059
Aug 24 17:43:30 debianl016 kernel: [ 339.447939] usb 1-2.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Aug 24 17:43:30 debianl016 kernel: [ 339.447953] usb 1-2.4: Product: Lighted Rockers 01-016
Aug 24 17:43:30 debianl016 kernel: [ 339.447964] usb 1-2.4: Manufacturer:
Aug 24 17:43:30 debianl016 kernel: [ 339.447976] usb 1-2.4: SerialNumber: 01-016
Aug 24 17:43:30 debianl016 mtp-probe: checking bus 1, device 12: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.4"
Aug 24 17:43:30 debianl016 mtp-probe: bus: 1, device: 12 was not an MTP device
Aug 24 17:46:27 debianl016 systemd-timesyncd[276]: interval/delta/delay/jitter/drift 512s/+0.002s/0.025s/0.005s/+53ppm
Aug 24 17:47:13 debianl016 minissdpd[753]: 1 new devices added
Aug 24 17:47:13 debianl016 minissdpd[753]: 1 new devices added
Aug 24 17:47:13 debianl016 minissdpd[753]: 1 new devices added
Aug 24 17:47:13 debianl016 minissdpd[753]: 1 new devices added
Aug 24 17:51:59 debianl016 pulseaudio[2839]: [pulseaudio] client-conf-x11.c: xcb_connection_has_error() returned true
Aug 24 17:51:59 debianl016 rtkit-daemon[1216]: Successfully made thread 2871 of process 2871 (/usr/bin/pulseaudio) owned by '2003' high priority at nice level -11.
Aug 24 17:51:59 debianl016 rtkit-daemon[1216]: Supervising 1 threads of 1 processes of 1 users.
Aug 24 17:51:59 debianl016 pulseaudio[2871]: [pulseaudio] main.c: Daemon startup without any loaded modules, refusing to work.
Aug 24 17:51:59 debianl016 pulseaudio[2839]: [pulseaudio] main.c: Daemon startup failed.
Aug 24 17:51:59 debianl016 pulseaudio[2870]: [pulseaudio] client-conf-x11.c: xcb_connection_has_error() returned true
Aug 24 17:51:59 debianl016 rtkit-daemon[1216]: Successfully made thread 2874 of process 2874 (/usr/bin/pulseaudio) owned by '2003' high priority at nice level -11.
Aug 24 17:51:59 debianl016 rtkit-daemon[1216]: Supervising 1 threads of 1 processes of 1 users.
Aug 24 17:51:59 debianl016 pulseaudio[2874]: [pulseaudio] main.c: Daemon startup without any loaded modules, refusing to work.
Aug 24 17:51:59 debianl016 pulseaudio[2870]: [pulseaudio] main.c: Daemon startup failed.
我还有一个正确的系统 A，其中使用 lightdm 正确配置了pulseaudio。系统 B 在 Gnome 上。两者都是 Debian 8 Jessie。
如何比较系统 A 和 B 之间的相关文件以避免这些与pulseaudio相关的错误？已验证：
/etc/pulse/系统 A 和 B 相同
编辑：彻底重新安装pulseaudio后，错误仍然存在。当前系统日志：
Aug 24 18:42:26 debianl016 pulseaudio[4461]: [pulseaudio] client-conf-x11.c: xcb_connection_has_error() returned true
Aug 24 18:42:26 debianl016 pulseaudio[4462]: [pulseaudio] client-conf-x11.c: xcb_connection_has_error() returned true
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Successfully made thread 4471 of process 4471 (/usr/bin/pulseaudio) owned by '2003' high priority at nice level -11.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Supervising 1 threads of 1 processes of 1 users.
Aug 24 18:42:26 debianl016 pulseaudio[4471]: [pulseaudio] module-alsa-card.c: Failed to find a working profile.
Aug 24 18:42:26 debianl016 pulseaudio[4471]: [pulseaudio] module.c: Failed to load module "module-alsa-card" (argument: "device_id="1" name="usb-CLASSIC_ORGAN_WORKS_CLASSIC_Lighted_Rockers_01-016_01-016-00-C01016" card_name="alsa_card.usb-CLASSIC_ORGAN_WORKS_CLASSIC_Lighted_Rockers_01-016_01-016-00-C01016" namereg_fail=false tsched=yes fixed_latency_range=no ignore_dB=no deferred_volume=yes use_ucm=yes card_properties="module-udev-detect.discovered=1""): initialization failed.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Supervising 1 threads of 1 processes of 1 users.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Successfully made thread 4483 of process 4471 (/usr/bin/pulseaudio) owned by '2003' RT at priority 5.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Supervising 2 threads of 1 processes of 1 users.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Supervising 2 threads of 1 processes of 1 users.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Successfully made thread 4484 of process 4471 (/usr/bin/pulseaudio) owned by '2003' RT at priority 5.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Supervising 3 threads of 1 processes of 1 users.
Aug 24 18:42:26 debianl016 pulseaudio[4471]: [pulseaudio] server-lookup.c: Unable to contact D-Bus: org.freedesktop.DBus.Error.Spawn.ExecFailed: /usr/bin/dbus-launch terminated abnormally with the following error: No protocol specified
Aug 24 18:42:26 debianl016 pulseaudio[4471]: [pulseaudio] server-lookup.c: Autolaunch error: X11 initialization failed.
Aug 24 18:42:26 debianl016 pulseaudio[4471]: [pulseaudio] main.c: Unable to contact D-Bus: org.freedesktop.DBus.Error.Spawn.ExecFailed: /usr/bin/dbus-launch terminated abnormally with the following error: No protocol specified
Aug 24 18:42:26 debianl016 pulseaudio[4471]: [pulseaudio] main.c: Autolaunch error: X11 initialization failed.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Successfully made thread 4488 of process 4488 (/usr/bin/pulseaudio) owned by '2003' high priority at nice level -11.
Aug 24 18:42:26 debianl016 rtkit-daemon[1216]: Supervising 4 threads of 2 processes of 1 users.
Aug 24 18:42:26 debianl016 pulseaudio[4488]: [pulseaudio] pid.c: Daemon already running.
脉冲音频--转储模块：
module-alsa-card ALSA Card
module-alsa-sink ALSA Sink
module-alsa-source ALSA Source
module-always-sink Always keeps at least one sink loaded even if it's a null one
module-augment-properties Augment the property sets of streams with additional static information
module-card-restore Automatically restore profile of cards
module-cli Command line interface
module-cli-protocol-tcp Command line interface protocol (TCP sockets)
module-cli-protocol-unix Command line interface protocol (UNIX sockets)
module-combine Compatibility module (module-combine rename)
module-combine-sink Combine multiple sinks to one
module-console-kit Create a client for each ConsoleKit session of this user
module-dbus-protocol D-Bus interface
module-default-device-restore Automatically restore the default sink and source
module-detect Detect available audio hardware and load matching drivers
module-device-manager Keep track of devices (and their descriptions) both past and present and prioritise by role
module-device-restore Automatically restore the volume/mute state of devices
module-echo-cancel Echo Cancellation
module-equalizer-sink General Purpose Equalizer
module-esound-sink ESOUND Sink
module-filter-apply Load filter sinks automatically when needed
module-filter-heuristics Detect when various filters are desirable
module-http-protocol-tcp HTTP (TCP sockets)
module-http-protocol-unix HTTP (UNIX sockets)
module-intended-roles Automatically set device of streams based on intended roles of devices
module-ladspa-sink Virtual LADSPA sink
module-loopback Loopback from source to sink
module-match Playback stream expression matching module
module-mmkbd-evdev Multimedia keyboard support via Linux evdev
module-native-protocol-fd Native protocol autospawn helper
module-native-protocol-tcp Native protocol (TCP sockets)
module-native-protocol-unix Native protocol (UNIX sockets)
module-null-sink Clocked NULL sink
module-null-source Clocked NULL source
module-oss OSS Sink/Source
module-pipe-sink UNIX pipe sink
module-pipe-source UNIX pipe source
module-position-event-sounds Position event sounds between L and R depending on the position on screen of the widget triggering them.
module-remap-sink Virtual channel remapping sink
module-remap-source Virtual channel remapping source
module-rescue-streams When a sink/source is removed, try to move its streams to the default sink/source
module-role-cork Mute & cork streams with certain roles while others exist
module-role-ducking Apply a ducking effect based on streams roles
module-rtp-recv Receive data from a network via RTP/SAP/SDP
module-rtp-send Read data from source and send it to the network via RTP/SAP/SDP
module-rygel-media-server UPnP MediaServer Plugin for Rygel
module-simple-protocol-tcp Simple protocol (TCP sockets)
module-simple-protocol-unix Simple protocol (UNIX sockets)
module-sine Sine wave generator
module-sine-source Sine wave generator source
module-stream-restore Automatically restore the volume/mute/device state of streams
module-suspend-on-idle When a sink/source is idle for too long, suspend it
module-switch-on-connect When a sink/source is added, switch to it
module-switch-on-port-available n/a
module-systemd-login Create a client for each login session of this user
module-tunnel-sink Tunnel module for sinks
module-tunnel-sink-new Create a network sink which connects via a stream to a remote PulseAudio server
module-tunnel-source Tunnel module for sources
module-tunnel-source-new Create a network source which connects via a stream to a remote PulseAudio server
module-udev-detect Detect available audio hardware and load matching drivers
module-virtual-sink Virtual sink
module-virtual-source Virtual source
module-virtual-surround-sink Virtual surround sink
module-volume-restore Compatibility module
module-x11-bell X11 bell interceptor
module-x11-cork-request Synthesize X11 media key events when cork/uncork is requested
module-x11-publish X11 credential publisher
module-x11-xsmp X11 session management
aplay -l：
**** List of PLAYBACK Hardware Devices ****
Failed to create secure directory (/run/user/1000/pulse): Permission denied
card 0: PCH [HDA Intel PCH], device 0: ALC887-VD Analog [ALC887-VD Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
kern.log 重新启动 MIDI 通信程序：
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to create secure directory (/run/user/1000/pulse): Permission denied
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to generate socket path.
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to load module "module-cli-protocol-unix" (argument: ""): initialization failed.
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to create secure directory (/run/user/1000/pulse): Permission denied
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to generate socket path.
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to load module "module-cli-protocol-unix" (argument: ""): initialization failed.
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to create secure directory (/run/user/1000/pulse): Permission denied
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to generate socket path.
Aug 25 10:42:43 debianl016 pulseaudio[1584]: Failed to load module "module-cli-protocol-unix" (argument: ""): initialization failed.
Aug 25 10:42:44 debianl016 pulseaudio[1584]: Failed to create secure directory (/run/user/1000/pulse): Permission denied
Aug 25 10:42:44 debianl016 pulseaudio[1584]: Failed to generate socket path.
Aug 25 10:42:44 debianl016 pulseaudio[1584]: Failed to load module "module-cli-protocol-unix" (argument: ""): initialization failed.
Aug 25 10:42:44 debianl016 pulseaudio[1584]: Failed to create secure directory (/run/user/1000/pulse): Permission denied
Aug 25 10:42:44 debianl016 pulseaudio[1584]: Failed to generate socket path.
Aug 25 10:42:44 debianl016 pulseaudio[1584]: Failed to load module "module-cli-protocol-unix" (argument: ""): initialization failed.
Aug 25 10:42:56 debianl016 pulseaudio[1584]: Failed to create secure directory (/run/user/1000/pulse): Permission denied
Aug 25 10:43:00 debianl016 pulseaudio[2110]: Stale PID file, overwriting.
Aug 25 10:43:00 debianl016 pulseaudio[2110]: Failed to find a working profile.
Aug 25 10:43:00 debianl016 pulseaudio[2110]: Failed to load module "module-alsa-card" (argument: "device_id="1" name="usb-CLASSIC_ORGAN_WORKS_CLASSIC_Lighted_Rockers_01-016_01-016-00-C01016" card_name="alsa_card.usb-CLASSIC_ORGAN_WORKS_CLASSIC_Lighted_Rockers_01-016_01-016-00-C01016" namereg_fail=false tsched=yes fixed_latency_range=no ignore_dB=no deferred_volume=yes use_ucm=yes card_properties="module-udev-detect.discovered=1""): initialization failed.
Aug 25 10:43:00 debianl016 pulseaudio[2110]: Unable to contact D-Bus: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
Aug 25 10:43:00 debianl016 pulseaudio[2110]: Unable to contact D-Bus: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
结论：为了让 MIDI 程序正常工作，我必须使用 apt-get purge pulseaudio 并删除 /usr/share/alsa 中的脉冲相关文件 - 似乎 pulseaudio 干扰了通信。
答案1
您似乎正在“覆盖”通常从系统范围文件中提取的配置，并使用属于当前用户的default.pa定位文件中的空白配置。这个特定于用户的配置文件可以在或目录default.pa中找到。如果找不到，可以运行locate：~/.pulse/default.pa~/.config/pulse/default.pa
sudo updatedb
locate default.pa
~/.config/pulse/除非您已经在使用用户特定的脉冲设置，否则您可以通过暂时“隐藏” （在某些系统上可能是~/.pulse) directory withmv ~/.config/pulse ~/.config/pulse.old` 并重新启动pulseaudio来测试解决方案。这将自动强制pulseaudio简单地恢复为使用默认的系统范围配置文件，因为它将是系统上找到的唯一一个。
此外，如果由于某种原因您的系统范围/etc/pulse/default.pa文件损坏，您可以使用以下命令重新安装它：
sudo apt-get -o Dpkg::Options::="--force-confask" install --reinstall pulseaudio