Debugging metadata variables
To debug the metadata variables, we can use the bitbake-getvar script. It uses the BitBake internal data to get a specific variable value and its attribution history.
For example, to inspect the PACKAGECONFIG variable for the procps recipe, we can use the following command:
Figure 10.7 – The result of bitbake-getvar -r procps PACKAGECONFIG
From Figure 10.7, we can see that PACKAGECONFIG at the end is empty. We can also see that defaultval was set to "${@bb.utils.filter('DISTRO_FEATURES', 'systemd', d)}" at line 33 from the meta/recipes-extended/procps/procps_3.3.17.bb file.
We can see the procps recipe lines 33 and 34 in the following screenshot:
Figure 10.8 - The procps recipe 33 and 34 lines
The bitbake-getvar script can be used to check whether a feature is enabled or to be sure a variable has been expanded as we expect.