Maven RELEASE and LATEST version "numbers" - maven

The -SNAPSHOT version qualifier is well explained in Oracle's "Understanding Maven Version Numbers".
But now I hear there is a RELEASE and LATEST version "numbers" as well. And at the same news item, that they are deprecated in Maven 3.
What are these RELEASE and LATEST version numbers/notations? Where can I learn more about them?

Copying answer from link provided by - glytching
Internally, Maven 2.x used the special version markers RELEASE and
LATEST to support automatic plugin version resolution. These
metaversions were also recognized in the element for a
declaration. For the sake of reproducible builds, Maven 3.x
no longer supports usage of these metaversions in the POM. As a
result, users will need to replace occurrences of these metaversions
with a concrete version.

Related

Does every dependency have a "latest" version in sbt/maven?

For example can I always use a "latest" version for every library as follows?
"com.kaala.re" %% "brain-builder-client" % "latest"
You can use LATEST for maven for any dependency, but it's DEPRECATED feature in maven 3.
When you depend on a plugin or a dependency, you can use the version
value of LATEST or RELEASE. LATEST refers to the latest released or
snapshot version of a particular artifact, the most recently deployed
artifact in a particular repository. RELEASE refers to the last
non-snapshot release in the repository. In general, it is not a best
practice to design software which depends on a non-specific version of
an artifact. If you are developing software, you might want to use
RELEASE or LATEST as a convenience so that you don't have to update
version numbers when a new release of a third-party library is
released. When you release software, you should always make sure that
your project depends on specific versions to reduce the chances of
your build or your project being affected by a software release not
under your control. Use LATEST and RELEASE with caution, if at all.

Should I use more recent plugin versions than default?

Maven by default uses these versions of plugins such as clean, compile, jar etc. if I don't override them in my pom.xml.
Should I be using more recent version of these plugins? For example, the current version of maven-compiler-plugin is 3.6.1 while the default is 2.5.1. Or, are the default versions reasonable enough that anyone not consciously depending on newer features need worry?
The maven way is "convention over configuration", so if you're wondering about not using the default parameters when running a maven build, you should have a specific use case that is not covered by the default version.
Here for example, (according to here) the install plugin is still at version 2.5.2, so that would point to me that using 2.5.1 is not such a bad choice by default.
I think the biggest difference comparing version (I might be wrong) is the upgrading of compatible version as for example this pseudo release note of the maven compiler.

How to manage Tycho / EAP versioning correctly

I have an Eclipse 4 project that is built using Tycho (0.19.0) and Maven (3.0-5)
During development of a version, say 1.0.0, the artifacts are configured with version 1.0.0-SNAPSHOT, and 1.0.0.qualifier depending on the files. When I want to release the version, I use the tycho-versions:set-version goal to change from 1.0.0-SNAPSHOT to 1.0.0.
I then build and copy the product to a remote share that publishes an update site so that older versions can be upgraded automatically at launch time.
Since I have some beta testers, I use more that one update site. One contains the stable versions, and my beta testers have one more update site to check at startup. The other one is actually an update site for snapshots that I have published, so those are not released versions of the product.
What I am experiencing seems strange: When the 1.0.0 application starts, it finds the previous snapshot (versioned 1.0.0.201312191455), thinks that those artifacts are more recent and updates itself back to an older version.
I'm guessing that Eclipse's version conventions state that x.y.z is older than x.y.z.u. Is that correct?
If so, then why does the tycho versions plugin remove the qualifier when a versions changes from snapshot to "release"? Doing so seems to make the artifacts look older than any of the snapshots. What's the correct way to handle this situation?
The answer was given in the tycho mailing list some time ago:
http://dev.eclipse.org/mhonarc/lists/tycho-user/msg01001.html
The details:
OSGi does not have a notion of "snapshot" versions, all versions are
treated the same and 1.0.0.qualifier is indeed considered to be newer
than 1.0.0.
There are two versioning schemes that result is reasonable behaviour
both for OSGi and Maven.
Use the same four part version (eg., 1.0.0.20111112-0735) for both Maven
and OSGi. This results in slightly odd version jump when going from
snapshots to releases on the maven side, i.e. 1.0.0-SNAPSHOT goes to
1.0.0.20111112-0735, but everything works otherwise.
Use even/odd convention to version snapshots and releases, i.e.
1.0.1-SNAPSHOT/1.0.1.qualifier is released as 1.0.2/1.0.2.
I think it is also possible to decouple maven and osgi versions of
released artifacts, i.e. use 1.0.0 for maven and 1.0.0.20111112-0735 for
OSGi, but personally I find this confusing and would not recommend. And
I am not sure if Tycho will allow this in the future.
--
Regards,
Igor

How to use maven version plugin in branch

I use maven version range for the dependencies in my parent pom.It works fine when I do a build on snapshot or a release.
But how should I need to proceed when I want to use the specific version of dependencies in a branch ?
For example: when I use version range such as (1.2.0,) it will always fetch the latest jar from the nexus repository. The latest would be like 1.2.5 as of when I do a release, since the dependencies are getting changed over and over.Now the latest version of my dependencies is 1.2.8-SNAPSHOT
In branch when I want 1.2.5 version for my dependencies, it is always looking for the latest one which is 1.2.5+
How to resolve this, while searching for similar questions I found that it could be resolved using maven-version-plugin. That requires a changes in the pom to add the plugin. But is there a solution without changing the pom and getting exact version for a dependency?
Any suggestions?
There is no solution without changing the pom at this point, if I understand the scenario correctly: In the release of a prior version of your product, the version of one (or more) of its dependencies was not fixated to the version available at the time. Now, in support of that previous release, the build has a different result than at the time of release.
There is no suggestion except to change the branch's pom to use the 'back' version available at the time of the release. Consider it a short term fix to a bug in the release process.

Is there a way to tell maven to always use the latest _stable_ version of a dependency?

How can I tell maven to always use the latest stable version of a dependency?
I know that I can depend on latest release version or just the latest version whatever that is from this question. I also know I can use the dependency plugin (also from that link).
However, I use google's guava library which seems to get an update every week. I find myself updating the version all the time. It's the google versioning system where it is more an incremental update than a big bang update and thus it is very unlikely that it will break anything especially given the nature of this library.
So I Would like to not have to keep changing the version identifier of my maven dependency.
So I could do this:
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>[12.0.1,)</version>
</dependency>
Which would give me version 12.0.1 and later... and since I don't depend on any repos that are going to supply any snap shot versions of this dependency this will ensure I always have the latest release version.
However, it will also give me the "rc" versions as well (13.0-rc1 and 13.0-rc2). This is what I want to avoid.
Is it possible to make maven only depend on the stable release? i.e. that don't have any "rc" or "beta" or "alhpa" in their name and are just plain "13.0".
You can use RELEASE value in version element for your dependency to make Maven use the latest released version. However this is not the best practice, because it can break build reproduceability.
Also, Maven don't make logical differences between versions like 12.0.1 and 13.0-rc1. From Maven's point of view both of them are released versions and basically what you're trying to do is breaking Maven releases ideology in several ways.
So, instead of versioning artifacts like 13.0-rc1, you should do a regular releases and use special repositories and artifact promotion process as par of your release. So, you could have a release-candidates repository that can be used during testing and once test pass you'll promote those artifacts to a final release repository. But if you need to make changes, you'll just update released version, so 13.0, 13.0.1, etc...
mvn versions:use-latest-releases -Dexcludes="*:*:*:*:*-M*,*:*:*:*:*RC*,*:*:*:*:*rc*,*:*:*:*:*-alpha*,*:*:*:*:*-beta*,*:*:*:*:20030203.000550,*:*:*:*:*Beta*"

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