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Diffstat (limited to 'documentation/ref-manual/technical-details.xml')
-rw-r--r-- | documentation/ref-manual/technical-details.xml | 59 |
1 files changed, 9 insertions, 50 deletions
diff --git a/documentation/ref-manual/technical-details.xml b/documentation/ref-manual/technical-details.xml index 5ef764c8e0..6bad547e50 100644 --- a/documentation/ref-manual/technical-details.xml +++ b/documentation/ref-manual/technical-details.xml | |||
@@ -901,56 +901,15 @@ | |||
901 | <title>Debugging</title> | 901 | <title>Debugging</title> |
902 | 902 | ||
903 | <para> | 903 | <para> |
904 | When things go wrong, debugging needs to be straightforward. | 904 | Seeing what metadata went into creating the input signature |
905 | Because of this, the Yocto Project includes strong debugging | 905 | of a shared state (sstate) task can be a useful debugging aid. |
906 | tools: | 906 | This information is available in signature information |
907 | <itemizedlist> | 907 | (<filename>siginfo</filename>) files in |
908 | <listitem><para>Whenever a shared state package is written | 908 | <link linkend='var-SSTATE_DIR'><filename>SSTATE_DIR</filename></link>. |
909 | out into the | 909 | For information on how to view and interpret information in |
910 | <link linkend='var-SSTATE_DIR'><filename>SSTATE_DIR</filename></link>, | 910 | <filename>siginfo</filename> files, see the |
911 | a corresponding <filename>.siginfo</filename> file is | 911 | "<link linkend='usingpoky-viewing-task-variable-dependencies'>Viewing Task Variable Dependencies</link>" |
912 | also written. | 912 | section. |
913 | This file contains a pickled Python database of all | ||
914 | the Metadata that went into creating the hash for a | ||
915 | given shared state package. | ||
916 | Whenever a stamp is written into the stamp directory | ||
917 | <link linkend='var-STAMP'><filename>STAMP</filename></link>, | ||
918 | a corresponding <filename>.sigdata</filename> file | ||
919 | is created that contains the same hash data that | ||
920 | represented the executed task. | ||
921 | </para></listitem> | ||
922 | <listitem><para>You can use BitBake to dump out the | ||
923 | signature construction information without executing | ||
924 | tasks by using either of the following BitBake | ||
925 | command-line options: | ||
926 | <literallayout class='monospaced'> | ||
927 | ‐‐dump-signatures=<replaceable>SIGNATURE_HANDLER</replaceable> | ||
928 | -S <replaceable>SIGNATURE_HANDLER</replaceable> | ||
929 | </literallayout> | ||
930 | <note> | ||
931 | Two common values for | ||
932 | <replaceable>SIGNATURE_HANDLER</replaceable> are | ||
933 | "none" and "printdiff" to only dump the signature | ||
934 | or to compare the dumped signature with the | ||
935 | cached one, respectively. | ||
936 | </note> | ||
937 | Using BitBake with either of these options causes | ||
938 | BitBake to dump out <filename>.sigdata</filename> files | ||
939 | in the stamp directory for every task it would have | ||
940 | executed instead of building the specified target | ||
941 | package. | ||
942 | </para></listitem> | ||
943 | <listitem><para>There is a | ||
944 | <filename>bitbake-diffsigs</filename> command that | ||
945 | can process <filename>.sigdata</filename> and | ||
946 | <filename>.siginfo</filename> files. | ||
947 | If you specify one of these files, BitBake dumps out | ||
948 | the dependency information in the file. | ||
949 | If you specify two files, BitBake compares the two | ||
950 | files and dumps out the differences between the two. | ||
951 | This more easily helps answer the question of "What | ||
952 | changed between X and Y?"</para></listitem> | ||
953 | </itemizedlist> | ||
954 | </para> | 913 | </para> |
955 | </section> | 914 | </section> |
956 | 915 | ||