When things go wrong, debugging needs to be straightforward. Because of this, the Yocto Project team included strong debugging tools:
Whenever a shared state package is written out, so is a
corresponding .siginfo
file.
This practice results in a pickled python database of all
the metadata that went into creating the hash for a given shared state
package.
If BitBake is run with the --dump-signatures
(or -S
) option, BitBake dumps out
.siginfo
files in
the stamp directory for every task it would have executed instead of
building the specified target package.
There is a bitbake-diffsigs
command that
can process these .siginfo
files.
If one file is specified, it will dump out the dependency
information in the file.
If two files are specified, it will compare the two files and dump out
the differences between the two.
This allows the question of "What changed between X and Y?" to be
answered easily.