<li><p>Mention which revision you are running. You can find this information in <spanclass="menu">About Haiku...</span> from the Deskbar menu. Also mention what kind of Haiku build you are testing (x86_gcc2, x86_64). The downloadable images are named accordingly, for a self-built image you should know how you built it.</p></li>
<p>When an application crashed, you can either save a report or write a core file (both saved to the Desktop) that you can attach to a bugreport, or you can evoke the <ahref="../../userguide/zh_CN/applications/debugger.html">Debugger</a>.</p>
<p>If it's not a crashing bug, you may get useful information when starting the application from Terminal. Some applications provide logging and other options when started with certain parameters; try <tt>-h</tt> or <tt>--help</tt> to see if that is the case. As example, see the different logging levels of <ahref="../../userguide/zh_CN/applications/haikudepot.html#logs">HaikuDepot</a>.</p>
<p>When vital servers like the app server, the registrar or the input server crash, you won't see the usual crash alert. Instead the whole screen will be cleared white and the Debugger will be started in text-mode, its output appearing directly on screen. Likely you will still be able to move the mouse, which will overwrite the white and Debugger output on screen. Applications still running (like ProcessController or the clock in the Deskbar) might also draw over the debugger output on screen.<br/>
Besides everything being more ugly and inconvenient, basically the same applies as for application bugs. Most importantly procure a back trace (<spanclass="cli">bt</span> command). You may need to take a picture of the screen with a digital camera, since you won't be able to copy the text anywhere.<br/>
Depending on what exactly crashed, you can try to save a crash report on the Desktop with <spanclass="cli">save-report</span> or <spanclass="cli">write-core</span> for a core file, and then press the power button once to try shutting cleanly down. If the power button doesn't work, there are also the commands <spanclass="cli">shutdown</span> and <spanclass="cli">reboot</span>.</p>
<p>If the system hasn't entered KDL by itself, you can do that intentionally by invoking the keyboard shortcut <spanclass="key">ALT</span><spanclass="key">SysReq</span><spanclass="key">D</span> (<spanclass="key">SysReq</span> being the <spanclass="key">Print</span> key, normally).<br/>
Note that in KDL your keyboard may not work. PS/2 keyboards always do, with USB keyboards it depends on the type of USB controller (UHCI/EHCI). Generally, the keyboard should be plugged into the port directly, not via any hubs. In some circumstances, the keyboard only works if one has entered KDL via the keyboard shortcut at least once. USB OHCI is not supported at the moment.</p>
<p>The option <spanclass="menu">Enable debug syslog</span> in the boot loader's <spanclass="menu">Debug menu</span> makes the syslog persistent. If the option <spanclass="menu">Save syslog from previous session during boot</span> is activated in the boot loader options (as it is by default), you'll find the syslog of your last session as <spanclass="path">/boot/system/var/log/previous_syslog</span>.<br/>
If you're not able to boot to get to the previous_syslog, you have to enter the boot loader menu by holding down <spanclass="key">SHIFT</span> (or <spanclass="key">SPACE</span> when booting via UEFI) while booting.<br/>
In the boot loader's <spanclass="menu">Debug menu</span> you should find the entries <spanclass="menu">Display syslog from previous session</span> and <spanclass="menu">Save syslog from previous session</span>. The former displays the syslog on screen, the latter allows you to save it as a file to disk. Note that at the moment only FAT32 volumes are supported for saving the file. If you want to use a USB stick, but have plugged it in too late so that it isn't recognized yet, you can reset the machine and re-enter the boot loader menu. Note: Don't accidentally boot any operating system or the data will be lost.</p>
<p><b>The on-screen debug output is useful only for debugging very specific issues and is known to have (timing) issues. Don't use it, if you don't have to.</b><br/>
This is only relevant when Haiku fails to boot on your machine and the <spanclass="menu">Debug syslog</span> option doesn't work for some reason. Before the Haiku boot logo appears, hold <spanclass="key">SHIFT</span> (or <spanclass="key">SPACE</span> when booting via UEFI) to enter the boot loader menu. Select <spanclass="menu">Select debug options</span>. Near the bottom, <spanclass="menu">Enable on screen debug output</span> will be listed. (Note: The other options could be enabled in an attempt to boot Haiku. If Haiku will boot only when one or more options are activated, be sure to mention which ones.)<br/>
Finally select <spanclass="menu">Return to main menu</span> and then <spanclass="menu">Continue booting</span>.<br/>
One or more pages of text will display on the screen, only the last few lines need to be included on your ticket. There's more information on the <ahref="../../userguide/zh_CN/bootloader.html">Boot Loader</a>.</p>
<tr><td>- <spanclass="cli">usb_hid_report</span></td><td></td><td>In case of USB input devices, add the <spanclass="cli">/tmp/usb_hid_report_descriptor_*.bin</span> file.</td></tr>
