bitbake: d.getVar("X", True) what does True mean?

Question

I find the following:

http://www.yoctoproject.org/docs/2.1/bitbake-user-manual/bitbake-user-manual.html#accessing-datastore-variables-using-python

It said that: Using "expand=True" expands the value. What does the "expand" means?

Answer 1

Great that you are reading BitBake user manual, it helps a lot in understanding the recipe syntax.

Returning to your question the 'expand' means that in case when this particular variable value depends on some other variables, e.g:

B = "architecture_${A}"

and A is equal to "x86", calling:

d.getVar("B", expand=True)

will return you: "architecture_x86" as the variable A has been expanded.

Some other examples can be found in BitBake User Manual Chapter 3.