Debugging does not always involve working with source code. Sometimes it is a change in an external factor that is causing the problem.
Strace is a tool that is useful for scenarios where we are looking for problems outside of the binary itself; for example, configuration files, input data, and kernel interfaces. This recipe will explain how to use it.
To include strace in your system, add the following to your conf/local.conf file:
IMAGE_INSTALL_append = " strace"
Strace is also part of the tools-debug image feature, so you can also add it with:
EXTRA_IMAGE_FEATURES += "tools-debug"
Strace is also included in the -sdk images.
Before starting, we will also include pgrep, a process utility that will make our debugging easier by looking up process IDs by name. To do so, add the following to your conf/local.conf configuration file:
IMAGE_INSTALL_append = " procps"