BitBake's -e
option is used to display
variable values after parsing.
The following command displays the variable values after the
configuration files (i.e. local.conf
,
bblayers.conf
,
bitbake.conf
and so forth) have been
parsed:
$ bitbake -e
The following command displays variable values after a specific recipe has been parsed. The variables include those from the configuration as well:
$ bitbake -e recipename
Each recipe has its own private set of variables (datastore). Internally, after parsing the configuration, a copy of the resulting datastore is made prior to parsing each recipe. This copying implies that variables set in one recipe will not be visible to other recipes.
Likewise, each task within a recipe gets a private datastore based on the recipe datastore, which means that variables set within one task will not be visible to other tasks.
In the output of bitbake -e
, each variable is
preceded by a description of how the variable got its value,
including temporary values that were later overriden.
This description also includes variable flags (varflags) set on
the variable.
The output can be very helpful during debugging.
Variables that are exported to the environment are preceded by
export
in the output of
bitbake -e
.
See the following example:
export CC="i586-poky-linux-gcc -m32 -march=i586 --sysroot=/home/ulf/poky/build/tmp/sysroots/qemux86"
In addition to variable values, the output of the
bitbake -e
and
bitbake -e
recipe
commands includes the following information:
The output starts with a tree listing all configuration
files and classes included globally, recursively listing
the files they include or inherit in turn.
Much of the behavior of the OpenEmbedded build system
(including the behavior of the
normal recipe build tasks)
is implemented in the
base
class and the classes it inherits, rather than being built
into BitBake itself.
After the variable values, all functions appear in the
output.
For shell functions, variables referenced within the
function body are expanded.
If a function has been modified using overrides or
using override-style operators like
_append
and
_prepend
, then the final assembled
function body appears in the output.