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author | Scott Rifenbark <srifenbark@gmail.com> | 2016-06-29 08:32:49 -0700 |
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committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2016-07-19 15:04:49 +0100 |
commit | b66e84e19d087f1f9fd279adc905f3a7bebbe8a1 (patch) | |
tree | 6a3dd7c88a2712894497ce74c06f8e325c9b814e /documentation/ref-manual | |
parent | 33e1c39361a21505f489cfa74b8ad27802a8ff38 (diff) | |
download | openembedded-core-contrib-b66e84e19d087f1f9fd279adc905f3a7bebbe8a1.tar.gz |
ref-manual: Updated the PR variable description.
Fixes [YOCTO #9843]
The variable description was very brief. These changes added some
substance to the description and how the OpenEmbedded build system
uses the variable.
(From yocto-docs rev: cc9117d4e16c56dd54f81804fda94561e61d91a7)
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/ref-manual')
-rw-r--r-- | documentation/ref-manual/ref-variables.xml | 42 |
1 files changed, 40 insertions, 2 deletions
diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml index 433893b93d..ed735a7eb3 100644 --- a/documentation/ref-manual/ref-variables.xml +++ b/documentation/ref-manual/ref-variables.xml @@ -9571,8 +9571,46 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" <glossdef> <para role="glossdeffirst"> <!-- <para role="glossdeffirst"><imagedata fileref="figures/define-generic.png" /> --> - The revision of the recipe. - The default value for this variable is "r0". + The revision of the recipe. The default value for this + variable is "r0". + Subsequent revisions of the recipe conventionally have the + values "r1", "r2", and so forth. + When + <link linkend='var-PV'><filename>PV</filename></link> + increases, <filename>PR</filename> is conventionally reset + to "r0". + <note> + The OpenEmbedded build system does not need the aid of + <filename>PR</filename> to know when to rebuild a + recipe. + The build system uses + <link linkend='var-STAMP'><filename>STAMP</filename></link> + and the + <link linkend='shared-state-cache'>shared state cache</link> + mechanisms. + </note> + The <filename>PR</filename> variable primarily becomes + significant when a package manager dynamically installs + packages on an already built image. + In this case, <filename>PR</filename>, which is the default + value of + <link linkend='var-PKGR'><filename>PKGR</filename></link>, + helps the package manager distinguish which package is the + most recent one in cases where many packages have the same + <filename>PV</filename> (i.e. <filename>PKGV</filename>). + Packages have the same <filename>PV</filename> usually + when the package manager installs the same upstream version + and some of the packages include packaging fixes. + <note> + <filename>PR</filename> does not need to be increased + for changes that do not change the package contents or + metadata. + </note> + Because, manually managing <filename>PR</filename> can be + cumbersome and error-prone, an automated solution exists. + See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#working-with-a-pr-service'>Working With a PR Service</ulink>" + section for more information. </para> </glossdef> </glossentry> |