| Summary: | Suggested clarification of the OVERRIDES glossary entry | ||
|---|---|---|---|
| Product: | [Documentation] Reference | Reporter: | ulfalizer |
| Component: | handbook | Assignee: | Scott Rifenbark <srifenbark> |
| Status: | RESOLVED FIXED | QA Contact: | |
| Severity: | normal | ||
| Priority: | Medium | CC: | bluelightning, poky.doc.watcher, poky.watcher, sgw, srifenbark |
| Version: | 2.2 | ||
| Target Milestone: | 2.2 M4 | ||
| Hardware: | x86 | ||
| OS: | Multiple | ||
| Whiteboard: | 01 Sept 2016: RESOLVED | ||
| OS type for building Yocto: | --- | Type of Regression: | --- |
| Verified: | Documentation change: | Done (doc changes complete) | |
Ulf, See http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html#var-OVERRIDES for updated OVERRIDES description in the glossary. Also, see http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html#var-PREFERRED_VERSION for the new note suggested. Thanks, Scott Hello, I think there's a missing "it" here: The set of overrides in OVERRIDES represents the "state" during building, which includes the current recipe being built, the machine for which <it> is being built, and so forth. Looks fine other than that. Thanks, Ulf Arghh.. I seem to be dropping words... sorry. Fixed - see http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html#var-OVERRIDES Setting to RESOLVED and putting the doc flag to "done." Scott |
Hello again, OVERRIDES (and overrides in general) is a bit tersely documented at the moment. Here's a suggestion for a new version that includes some examples, mentions standard override-related variables, and explains the _pn-${PN} override: OVERRIDES: A colon-separated list of overrides that currently apply. Overrides are a BitBake mechanism that allows variables to be selectively overridden at the end of parsing. The set of overrides in OVERRIDES is meant to represent the "state" during building, including the current recipe being built, the machine it is being built for, etc. As an example, if the string "an-override" appears as an element in the colon-separated list in OVERRIDES, then the following assignment will override FOO with the value "overridden" at the end of parsing: FOO_an-override = "overridden" See the "Conditional Syntax (Overrides)" section of the BitBake User Manual for more information on the overrides mechanism. The default value of OVERRIDES includes the values of the [CLASSOVERRIDE], [MACHINEOVERRIDES], and [DISTROOVERRIDES] variables. Another important override included by default is pn-${PN}. This override allows variables to be set for a single recipe within configuration (.conf) files, like in the following example: FOO_pn-myrecipe = "myrecipe-specific value" An easy way to see what overrides apply is to search for OVERRIDES in the output of [bitbake -e](http://www.yoctoproject.org/docs/2.2/ref-manual/ref-manual.html#usingpoky-debugging-viewing-variable-values). In addition, the following note could be added to the end of the PREFERRED_VERSION glossary entry: Note { The _forcevariable override is not handled specially. It only works because the default value of [OVERRIDES] includes "forcevariable". } Cheers, Ulf