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bitbake: user-manual-metadata: Editing pass over the manual chapter 

(Bitbake rev: 6f326f2f2785d6d48d7753abee6e8162852d8702)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Richard Purdie 2014-01-18 14:02:18 +00:00
parent 98b41e41ff
commit c8892fc919
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bitbake/doc/user-manual/user-manual-metadata.xml
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@ -5,21 +5,27 @@
<title>Metadata</title> <title>Metadata</title>
<section> <section>
<title>Description</title> <title>Overview</title>
<itemizedlist>
<para>BitBake metadata can be classified into 3 major areas:</para>
<listitem>
<para>Configuration Files</para>
</listitem>
<listitem>
<para>.bb Files</para>
</listitem>
<listitem>
<para>Classes</para>
</listitem>
</itemizedlist>
<para> <para>
What follows are a large number of examples of BitBake metadata. Any syntax which isn't supported The BitBake task executor together with various types of configuration files form the OpenEmbedded
Core.
This section provides an overview of the BitBake task executor and the configuration files by
describing what they are used for and how they interact.
</para>
<para>
BitBake handles the parsing and execution of the data files. The data itself is of various types:
<itemizedlist>
<listitem><para><emphasis>Recipes:</emphasis>
Provides details about particular pieces of software.</para></listitem>
<listitem><para><emphasis>Class Data:</emphasis>
An abstraction of common build information (e.g. how to build a Linux kernel).</para></listitem>
<listitem><para><emphasis>Configuration Data:</emphasis>
Defines machine-specific settings, policy decisions, etc. Configuration data acts
as the glue to bind everything together.</para></listitem>
</itemizedlist>
What follows are a large number of examples of BitBake metadata. Any syntax which isn't supported
in any of the aforementioned areas will be documented as such. in any of the aforementioned areas will be documented as such.
</para> </para>
</section> </section>
@ -28,7 +34,7 @@
<title>Basic Syntax</title> <title>Basic Syntax</title>
<section id='basic-variable-setting'> <section id='basic-variable-setting'>
<title>Basic variable setting</title> <title>Basic Variable Setting</title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
@ -39,7 +45,7 @@
</section> </section>
<section id='variable-expansion'> <section id='variable-expansion'>
<title>Variable expansion</title> <title>Variable Expansion</title>
<para> <para>
BitBake supports variables referencing one another's BitBake supports variables referencing one another's
@ -69,8 +75,10 @@
it will retain its previous value. it will retain its previous value.
If <filename>A</filename> is unset prior to the above call, If <filename>A</filename> is unset prior to the above call,
<filename>A</filename> will be set to <filename>aval</filename>. <filename>A</filename> will be set to <filename>aval</filename>.
Note that this assignment is immediate, so if there are multiple ?= assignments <note>
This assignment is immediate, so if there are multiple "?=" assignments
to a single variable, the first of those will be used. to a single variable, the first of those will be used.
</note>
</para> </para>
</section> </section>
@ -86,11 +94,11 @@
it will retain that value. it will retain that value.
If <filename>A</filename> is unset prior to the above, If <filename>A</filename> is unset prior to the above,
<filename>A</filename> will be set to <filename>someothervalue</filename>. <filename>A</filename> will be set to <filename>someothervalue</filename>.
This is a lazy/weak assignment in that the assignment does not occur until the end This is a lazy or weak assignment in that the assignment does not occur until the end
of the parsing process, so that the last, rather than the first, of the parsing process, so that the last, rather than the first,
??= assignment to a given variable will be used. "??=" assignment to a given variable will be used.
Any other setting of <filename>A</filename> using = or ?= Any other setting of <filename>A</filename> using "=" or "?="
will however override the value set with ??= will, however, override the value set with "??=".
</para> </para>
</section> </section>
@ -98,8 +106,9 @@
<title>Immediate variable expansion (:=)</title> <title>Immediate variable expansion (:=)</title>
<para> <para>
:= results in a variable's contents being expanded immediately, rather than when the variable is actually used. The ":=" operator results in a variable's contents being expanded immediately,
<literallayout class='monospaced'> rather than when the variable is actually used:
<literallayout class='monospaced'>
T = "123" T = "123"
A := "${B} ${A} test ${T}" A := "${B} ${A} test ${T}"
T = "456" T = "456"
@ -107,7 +116,7 @@
C = "cval" C = "cval"
C := "${C}append" C := "${C}append"
</literallayout> </literallayout>
In that example, <filename>A</filename> would contain In this example, <filename>A</filename> would contain
<filename>test 123</filename>, <filename>B</filename> would contain <filename>test 123</filename>, <filename>B</filename> would contain
<filename>456 bval</filename>, and <filename>C</filename> <filename>456 bval</filename>, and <filename>C</filename>
would be <filename>cvalappend</filename>. would be <filename>cvalappend</filename>.
@ -131,7 +140,7 @@
</section> </section>
<section id='appending-and-prepending-without-spaces'> <section id='appending-and-prepending-without-spaces'>
<title>Appending (.=) and prepending (=.) without spaces</title> <title>Appending (.=) and Prepending (=.) Without Spaces</title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
@ -149,7 +158,7 @@
</section> </section>
<section id='appending-and-prepending-override-style-syntax'> <section id='appending-and-prepending-override-style-syntax'>
<title>Appending and Prepending (override style syntax)</title> <title>Appending and Prepending (Override Style Syntax)</title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
@ -159,18 +168,20 @@
C_prepend = "additional data " C_prepend = "additional data "
</literallayout> </literallayout>
This example results in <filename>B</filename> This example results in <filename>B</filename>
becoming <filename>bval additional data</filename> becoming <filename>bval additional data</filename> and
and <filename>C</filename> becoming <filename>C</filename> becoming
<filename>additional data cval</filename>. <filename>additional data cval</filename>.
Note the spaces in the <filename>_append</filename>. <note>
Unlike the += operator, additional space is not automatically added. The spaces in <filename>_append</filename>.
You must take steps to add space Unlike the "+=" operator, additional space is not automatically added.
yourself. You must take steps to add space yourself.
</note>
</para> </para>
</section> </section>
<section id='removing-override-style-syntax'> <section id='removing-override-style-syntax'>
<title>Removing (override style syntax)</title> <title>Removing (Override Style Syntax)</title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
FOO = "123 456 789 123456 123 456 123 456" FOO = "123 456 789 123456 123 456 123 456"
@ -182,7 +193,7 @@ yourself.
</section> </section>
<section id='variable-flags'> <section id='variable-flags'>
<title>Variable flags</title> <title>Variable Flags</title>
<para> <para>
Variables can have associated flags which provide a way of tagging extra information onto a variable. Variables can have associated flags which provide a way of tagging extra information onto a variable.
@ -192,12 +203,12 @@ yourself.
VARIABLE[SOMEFLAG] = "value" VARIABLE[SOMEFLAG] = "value"
</literallayout> </literallayout>
In this example, <filename>VARIABLE</filename> has a flag, In this example, <filename>VARIABLE</filename> has a flag,
<filename>SOMEFLAG</filename> which is set to <filename>value</filename>. <filename>SOMEFLAG</filename> that is set to <filename>value</filename>.
</para> </para>
</section> </section>
<section id='inline-python-variable-expansion'> <section id='inline-python-variable-expansion'>
<title>Python variable expansion</title> <title>Inline Python Variable Expansion</title>
<para> <para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
@ -207,18 +218,22 @@ yourself.
variable containing today's date. variable containing today's date.
</para> </para>
</section> </section>
</section>
<section id='conditional-syntax-overrides'> <section id='conditional-syntax-overrides'>
<title>Conditional metadata set</title> <title>Conditional Syntax (Overrides)</title>
<section id='conditional-metadata'>
<title>Conditional Metadata</title>
<para> <para>
<filename>OVERRIDES</filename> is a <quote>:</quote> separated variable containing <filename>OVERRIDES</filename> is a “:” separated variable containing
each item you want to satisfy conditions. each item for which you want to satisfy conditions.
So, if you have a variable which is conditional on <quote>arm</quote>, and <quote>arm</quote> So, if you have a variable that is conditional on “arm”, and “arm”
is in <filename>OVERRIDES</filename>, then the <quote>arm</quote> specific is in <filename>OVERRIDES</filename>, then the “arm” specific
version of the variable is used rather than the non-conditional version of the variable is used rather than the non-conditional
version. version.
Example: Here is an example:
<literallayout class='monospaced'> <literallayout class='monospaced'>
OVERRIDES = "architecture:os:machine" OVERRIDES = "architecture:os:machine"
TEST = "defaultvalue" TEST = "defaultvalue"
@ -227,16 +242,17 @@ yourself.
</literallayout> </literallayout>
In this example, <filename>TEST</filename> would be In this example, <filename>TEST</filename> would be
<filename>osspecificvalue</filename>, due to the condition <filename>osspecificvalue</filename>, due to the condition
<quote>os</quote> being in <filename>OVERRIDES</filename>. “os” being in <filename>OVERRIDES</filename>.
</para> </para>
</section> </section>
<section id='conditional-appending'> <section id='conditional-appending'>
<title>Conditional appending</title> <title>Conditional Appending</title>
<para> <para>
BitBake also supports appending and prepending to variables based BitBake also supports appending and prepending to variables based
on whether something is in <filename>OVERRIDES</filename>. Example: on whether something is in <filename>OVERRIDES</filename>.
Here is an example:
<literallayout class='monospaced'> <literallayout class='monospaced'>
DEPENDS = "glibc ncurses" DEPENDS = "glibc ncurses"
OVERRIDES = "machine:local" OVERRIDES = "machine:local"
@ -248,22 +264,22 @@ yourself.
</section> </section>
<section id='variable-interaction-worked-examples'> <section id='variable-interaction-worked-examples'>
<title>Variable interaction: Worked Examples</title> <title>Variable Interaction: Worked Examples</title>
<para> <para>
Despite the documentation of the different forms of Despite the documentation of the different forms of
variable definition above, it can be hard to work variable definition above, it can be hard to work
out what happens when variable operators are combined. out what happens when variable operators are combined.
This section documents some common questions people have </para>
regarding the way variables interact.
<para>
Following are some common scenarios where variables interact
that can confuse users.
</para> </para>
<para> <para>
There is often confusion about which order overrides and the There is often confusion about which order overrides and the
various append operators take effect. various "append" operators take effect:
</para>
<para>
<literallayout class='monospaced'> <literallayout class='monospaced'>
OVERRIDES = "foo" OVERRIDES = "foo"
A_foo_append = "X" A_foo_append = "X"
@ -297,7 +313,7 @@ yourself.
A .= "5" A .= "5"
</literallayout> </literallayout>
Would ultimately result in <filename>A</filename> taking the value Would ultimately result in <filename>A</filename> taking the value
"1 4523" since the _append operator executes at the "1 4523" since the "_append" operator executes at the
same time as the expansion of other overrides. same time as the expansion of other overrides.
</para> </para>
</section> </section>
@ -306,7 +322,7 @@ yourself.
<title>Key Expansion</title> <title>Key Expansion</title>
<para> <para>
Key expansion happens at the data store finalisation Key expansion happens at the data store finalization
time just before overrides are expanded. time just before overrides are expanded.
<literallayout class='monospaced'> <literallayout class='monospaced'>
A${B} = "X" A${B} = "X"
@ -322,10 +338,13 @@ yourself.
<title>Inheritance</title> <title>Inheritance</title>
<section id='inheritance-directive'> <section id='inheritance-directive'>
<title>Inheritance</title> <title>Inheritance Directive</title>
<para><emphasis>NOTE:</emphasis>
This is only supported in .bb and .bbclass files. <note>
</para> This is only supported in <filename>.bb</filename> and
<filename>.bbclass</filename> files.
</note>
<para> <para>
The inherit directive is a means of specifying what classes The inherit directive is a means of specifying what classes
of functionality your <filename>.bb</filename> requires. of functionality your <filename>.bb</filename> requires.
@ -339,34 +358,42 @@ yourself.
</section> </section>
<section id='inclusion-directive'> <section id='inclusion-directive'>
<title>Inclusion</title> <title>Inclusion Directive</title>
<para> <para>
Next, there is the <filename>include</filename> directive, which causes BitBake to parse whatever file you specify, This directive causes BitBake to parse whatever file you specify,
and insert it at that location, which is not unlike <command>make</command>. and insert it at that location, which is not unlike Make.
However, if the path specified on the <filename>include</filename> line is a However, if the path specified on the include line is a
relative path, BitBake will locate the first one it can find relative path, BitBake will locate the first one it can find
within <filename>BBPATH</filename>. within <filename>BBPATH</filename>.
</para> </para>
</section> </section>
<section id='requiring-inclusion'> <section id='requiring-inclusion'>
<title>Requiring inclusion</title> <title>Requiring Inclusion</title>
<para> <para>
In contrast to the <filename>include</filename> directive, <filename>require</filename> will In contrast to the include directive, require will raise a
raise an
ParseError if the file to be included cannot ParseError if the file to be included cannot
be found. be found.
Otherwise it will behave just like the <filename>include</filename> directive. Otherwise it will behave just like the include directive.
</para> </para>
</section> </section>
</section> </section>
<section id='defining-python-functions-into-the-global-python-namespace'> <section id='defining-python-functions-into-the-global-python-namespace'>
<title>Defining Python functions into the global Python namespace</title> <title>Defining Python Functions into the Global Python Namespace</title>
<para><emphasis>NOTE:</emphasis> This is only supported in .bb and .bbclass files <note>
<para>
This is only supported in <filename>.bb</filename>
and <filename>.bbclass</filename> files.
</para>
<para>
Python functions are in the global namespace so should use
unique names.
<literallayout class='monospaced'> <literallayout class='monospaced'>
def get_depends(d): def get_depends(d):
if d.getVar('SOMECONDITION', True): if d.getVar('SOMECONDITION', True):
@ -376,8 +403,10 @@ raise an
SOMECONDITION = "1" SOMECONDITION = "1"
DEPENDS = "${@get_depends(d)}" DEPENDS = "${@get_depends(d)}"
</literallayout> </literallayout>
This would result in <filename>DEPENDS</filename> containing <filename>dependencywithcond</filename>. This would result in <filename>DEPENDS</filename>
containing <filename>dependencywithcond</filename>.
</para> </para>
</note>
</section> </section>
<section> <section>
@ -436,15 +465,15 @@ python do_printdate () {
<title>Configuration files</title> <title>Configuration files</title>
<para> <para>
The first kind of metadata in BitBake is configuration metadata. The first kind of metadata in BitBake is configuration metadata.
This metadata is global, and therefore affects <emphasis>all</emphasis> packages and This metadata is global, and therefore affects all packages and
tasks which are executed. tasks that are executed.
</para> </para>
<para> <para>
BitBake will first search the current working directory for an BitBake will first search the current working directory for an
optional <filename>conf/bblayers.conf</filename> configuration file. optional <filename>conf/bblayers.conf</filename> configuration file.
This file is expected to contain a <filename>BBLAYERS</filename> This file is expected to contain a <filename>BBLAYERS</filename>
variable which is a space delimited list of 'layer' directories. variable that is a space delimited list of 'layer' directories.
For each directory in this list, a <filename>conf/layer.conf</filename> For each directory in this list, a <filename>conf/layer.conf</filename>
file will be searched for and parsed with the file will be searched for and parsed with the
<filename>LAYERDIR</filename> variable being set to the directory where <filename>LAYERDIR</filename> variable being set to the directory where
@ -456,10 +485,10 @@ python do_printdate () {
<para> <para>
BitBake will then expect to find <filename>conf/bitbake.conf</filename> BitBake will then expect to find <filename>conf/bitbake.conf</filename>
somewhere in the user specified <filename>BBPATH</filename>. file somewhere in the user specified <filename>BBPATH</filename>.
That configuration file generally has include directives to pull That configuration file generally has include directives to pull
in any other metadata (generally files specific to architecture, in any other metadata (generally files specific to architecture,
machine, <emphasis>local</emphasis> and so on). machine, local and so on).
</para> </para>
<para> <para>
@ -467,8 +496,10 @@ python do_printdate () {
in <filename>.conf</filename> files. in <filename>.conf</filename> files.
</para> </para>
</section> </section>
<section id='classes'> <section id='classes'>
<title>Classes</title> <title>Classes</title>
<para> <para>
BitBake classes are our rudimentary inheritance mechanism. BitBake classes are our rudimentary inheritance mechanism.
As briefly mentioned in the metadata introduction, they're As briefly mentioned in the metadata introduction, they're
@ -479,15 +510,15 @@ python do_printdate () {
</section> </section>
<section id='bb-files'> <section id='bb-files'>
<title>.<filename>.bb</filename> files</title> <title><filename>.bb</filename> Files</title>
<para> <para>
BitBake (<filename>.bb</filename>) file is a logical unit A BitBake (<filename>.bb</filename>) file is a logical unit
of tasks to be executed. of tasks to be executed.
Normally this is a package to be built. Normally this is a package to be built.
Inter-<filename>.bb</filename> dependencies are obeyed. Inter-<filename>.bb</filename> dependencies are obeyed.
The files themselves are located via The files themselves are located via the
the <filename>BBFILES</filename> variable, which <filename>BBFILES</filename> variable, which
is set to a space separated list of <filename>.bb</filename> is set to a space separated list of <filename>.bb</filename>
files, and does handle wildcards. files, and does handle wildcards.
</para> </para>
@ -497,17 +528,17 @@ python do_printdate () {
<section id='events'> <section id='events'>
<title>Events</title> <title>Events</title>
<para> <note>
<emphasis>NOTE:</emphasis> This is only supported in <filename>.bb</filename>
This is only supported in <filename>.bb</filename>
and <filename>.bbclass</filename> files. and <filename>.bbclass</filename> files.
</para> </note>
<para> <para>
BitBake allows installation of event handlers. BitBake allows installation of event handlers.
Events are triggered at certain points during operation, Events are triggered at certain points during operation,
such as the beginning of operation against a given such as the beginning of operation against a given
<filename>.bb</filename>, the start of a given task, <filename>.bb</filename>, the start of a given task,
task failure, task success, et cetera. task failure, task success, and so forth.
The intent is to make it easy to do things like email The intent is to make it easy to do things like email
notification on build failure. notification on build failure.
<literallayout class='monospaced'> <literallayout class='monospaced'>
@ -521,9 +552,9 @@ python do_printdate () {
</literallayout> </literallayout>
This event handler gets called every time an event is This event handler gets called every time an event is
triggered. triggered.
A global variable <filename>e</filename> is defined. A global variable "<filename>e</filename>" is defined.
<filename>e.data</filename> contains an instance of "<filename>e.data</filename>" contains an instance of
<filename>bb.data</filename>. "<filename>bb.data</filename>".
With the <filename>getName(e)</filename> method one can get With the <filename>getName(e)</filename> method one can get
the name of the triggered event. the name of the triggered event.
</para> </para>
@ -535,7 +566,7 @@ python do_printdate () {
</section> </section>
<section id='variants-class-extension-mechanism'> <section id='variants-class-extension-mechanism'>
<title>Variants</title> <title>Variants - Class Extension Mechanism</title>
<para> <para>
Two BitBake features exist to facilitate the creation of Two BitBake features exist to facilitate the creation of
@ -546,15 +577,12 @@ python do_printdate () {
The first is <filename>BBCLASSEXTEND</filename>. The first is <filename>BBCLASSEXTEND</filename>.
This variable is a space separated list of classes used to "extend" the This variable is a space separated list of classes used to "extend" the
recipe for each variant. recipe for each variant.
As an example, setting Here is an example that results in a second incarnation of the current
recipe being available.
This second incarnation will have the "native" class inherited.
<literallayout class='monospaced'> <literallayout class='monospaced'>
BBCLASSEXTEND = "native" BBCLASSEXTEND = "native"
</literallayout> </literallayout>
results in a second incarnation of the current
recipe being available.
This second incarnation will have the "native" class inherited.
</para>
<para>
The second feature is <filename>BBVERSIONS</filename>. The second feature is <filename>BBVERSIONS</filename>.
This variable allows a single recipe to build multiple versions of a This variable allows a single recipe to build multiple versions of a
project from a single recipe file, and allows you to specify project from a single recipe file, and allows you to specify
@ -568,7 +596,7 @@ python do_printdate () {
BBVERSIONS = "1.0.[0-6]:1.0.0+ \ 1.0.[7-9]:1.0.7+" BBVERSIONS = "1.0.[0-6]:1.0.0+ \ 1.0.[7-9]:1.0.7+"
SRC_URI_append_1.0.7+ = "file://some_patch_which_the_new_versions_need.patch;patch=1" SRC_URI_append_1.0.7+ = "file://some_patch_which_the_new_versions_need.patch;patch=1"
</literallayout> </literallayout>
Note that the name of the range will default to the original version of the The name of the range will default to the original version of the
recipe, so given OE, a recipe file of <filename>foo_1.0.0+.bb</filename> recipe, so given OE, a recipe file of <filename>foo_1.0.0+.bb</filename>
will default the name of its versions to <filename>1.0.0+</filename>. will default the name of its versions to <filename>1.0.0+</filename>.
This is useful, as the range name is not only placed into overrides; This is useful, as the range name is not only placed into overrides;
@ -579,17 +607,21 @@ python do_printdate () {
</section> </section>
<section id='dependencies'> <section id='dependencies'>
<title>Dependency handling</title> <title>Dependencies</title>
<section id='dependencies-overview'>
<title>Overview</title>
<para> <para>
BitBake handles dependencies at the task level since to BitBake handles dependencies at the task level since to
allow for efficient operation with multiple allow for efficient operation with multiple
processed executing in parallel. A robust method of processes executing in parallel, a robust method of
specifying task dependencies is therefore needed. specifying task dependencies is needed.
</para> </para>
</section>
<section id='dependencies-internal-to-the-bb-file'> <section id='dependencies-internal-to-the-bb-file'>
<title>Dependencies internal to the <filename>.bb</filename> file</title> <title>Dependencies Internal to the <filename>.bb</filename> File</title>
<para> <para>
Where the dependencies are internal to a given Where the dependencies are internal to a given
@ -609,7 +641,7 @@ python do_printdate () {
<literallayout class='monospaced'> <literallayout class='monospaced'>
do_configure[deptask] = "do_populate_staging" do_configure[deptask] = "do_populate_staging"
</literallayout> </literallayout>
means the <filename>do_populate_staging</filename> In the previous example, the <filename>do_populate_staging</filename>
task of each item in <filename>DEPENDS</filename> must have completed before task of each item in <filename>DEPENDS</filename> must have completed before
<filename>do_configure</filename> can execute. <filename>do_configure</filename> can execute.
</para> </para>
@ -628,7 +660,7 @@ python do_printdate () {
<literallayout class='monospaced'> <literallayout class='monospaced'>
do_package_write[rdeptask] = "do_package" do_package_write[rdeptask] = "do_package"
</literallayout> </literallayout>
means the <filename>do_package</filename> In the previous example, the <filename>do_package</filename>
task of each item in <filename>RDEPENDS</filename> must have task of each item in <filename>RDEPENDS</filename> must have
completed before <filename>do_package_write</filename> can execute. completed before <filename>do_package_write</filename> can execute.
</para> </para>
@ -639,7 +671,7 @@ python do_printdate () {
<para> <para>
These are specified with the 'recrdeptask' flag These are specified with the 'recrdeptask' flag
which is used signify the task(s) of dependencies which is used to signify the task(s) of dependencies
which must have completed before that task can be which must have completed before that task can be
executed. executed.
It works by looking though the build It works by looking though the build
@ -655,29 +687,29 @@ python do_printdate () {
dependencies of those tasks but through the dependencies of those tasks but through the
build and runtime dependencies of dependent tasks too. build and runtime dependencies of dependent tasks too.
If that is the case, the taskname itself should If that is the case, the taskname itself should
be referenced in the task list, e.g. be referenced in the task list (e.g.
<filename>do_a[recrdeptask] = "do_a do_b"</filename>. <filename>do_a[recrdeptask] = "do_a do_b"</filename>).
</para> </para>
</section> </section>
<section id='inter-task-dependencies'> <section id='inter-task-dependencies'>
<title>Inter task</title> <title>Inter-Task Dependencies</title>
<para> <para>
The 'depends' flag for tasks is a more generic form of which The 'depends' flag for tasks is a more generic form which
allows an interdependency on specific tasks rather than specifying allows an inter-dependency on specific tasks rather than specifying
the data in <filename>DEPENDS</filename>. the data in <filename>DEPENDS</filename>.
<literallayout class='monospaced'> <literallayout class='monospaced'>
do_patch[depends] = "quilt-native:do_populate_staging" do_patch[depends] = "quilt-native:do_populate_staging"
</literallayout> </literallayout>
means the <filename>do_populate_staging</filename> In the previous example, the <filename>do_populate_staging</filename>
task of the target quilt-native must have completed before the task of the target quilt-native must have completed before the
<filename>do_patch</filename> task can execute. <filename>do_patch</filename> task can execute.
</para> </para>
<para> <para>
The 'rdepends' flag works in a similar way but takes targets The 'rdepends' flag works in a similar way but takes targets
in the runtime namespace instead of the build time dependency in the runtime namespace instead of the build-time dependency
namespace. namespace.
</para> </para>
</section> </section>