Version policy for OE recipes
There is general confusion about what a correct PV string should look like. This page attempts to define a standard for packages in OpenEmbedded to follow. Whilst not mandatory, it is strongly recommended.
OE's versioning policy aims to follow that of Debian (and is hence compatible with ipkg).
Debian's PV policy can be viewed at 
One key phrase to note is "The lexical comparison is a comparison of ASCII values modified so that all the letters sort earlier than all the non-letters." This means characters like + and - have a higher priority than alphanumeric characters. If in doubt, experiment with the ipkg-compare-versions program from ipkg-utils.
Our current policy is:
- PN may contain hypens
- PV should avoid containing hypens
- PR must not contain hyphens
It is a common misconception that hyphens are not allowed in PV. Looking at packages/linux shows they can be used but extreme caution is recommended (see pitfalls below). They wouldn't be allowed under Debian rules if PR wasn't specificed but since OE always sets PR by default, hyphens are allowed by default.
Date based packages
The current policy is to use the format PV = "1.2+scmYYYYMMDD".
- cvs packages should use <latest released version>+cvs<date>, e.g. foo_1.3+cvs20051106
- svn packages should use <latest released version>+svn<date>, e.g. foo_1.3+svn20051106
Prerelease packages such as
cause a lot of trouble with package managers when foo_2.4.4 gets released. So we should use the following: