For development, it is often easier to dump the crash information in the logs as the crash happens on device. For devices in the field, reports may be sent to a remote crash server, as access to the devices' logs might not be available. The fuchsia.net.http.Loader protocol is used to talk to the remote crash server. Whether reports are uploaded is controlled via Assembly.
To test your changes, on a real device, we have some unit tests and some helper programs to simulate various crashes. For the helper programs, you first need to apply a developer override to enable uploads on an eng device. For example, the userdebug config enables crash report uploading if the privacy settings also have it enabled.
First, define one or more developer overrides in //local/BUILD.gn. This file is Git-ignored so you can add it once and only use/modify as needed:
import("//build/assembly/developer_overrides.gni")
assembly_developer_overrides("feedback_userdebug_config") {
developer_only_options = {
forensics_options = {
build_type_override = "userdebug"
}
}
}
You can apply an override via fx set using a label from //local/BUILD.gn, such as: product_assembly_overrides_label = "//local:feedback_userdebug_config".
Alternatively, overrides can be specified in-line in args.gn:
product_assembly_overrides_contents = {
developer_only_options = {
forensics_options = {
build_type_override = "userdebug"
}
}
}
Valid options for build_type_override are user, userdebug and eng_with_upload.
Note, the above overrides only work for eng builds and product assembly will fail if used on user/userdebug builds.
Then, after running each one of the helper programs (see commands in sections below), you should then look each time for the following line in the syslog:
(host)$ ffx log --tag forensics ... Successfully uploaded report at $URL... ...
Click on the URL (contact OWNERS if you don't have access and think you should) and check that the report matches your expectations, e.g., the new annotation is set to the expected value.
To run the unit and integration tests:
(host) $ fx test //src/developer/forensics
The following command causes the root job to be terminated due to a critical process death:
(host)$ ffx component stop archivist.cm
The device will then reboot and the system should detect the kernel crash log, attach it to a crash report and try to upload it. Look at the syslog upon reboot.
The following command will cause a write to address 0x0:
(target)$ crasher
You can immediately look at the syslog.
Contact OWNERS.