How do I make a branch from a SVN tag with Maven?

Question

Suppose I have tagged the release version of our project under $SVNROOT/project/tags/1.0. Suppose now that I need to create a branch from that tag, mark it as being a SNAPSHOT, and update the scm configuration.

I tried with the release:prepare goal thus:

$ svn co $SVNROOT/project/tags/1.0 project-1.0
$ cd project-1.0
$ mvn release:branch -DbranchName=project-1.0.X -DupdateBranchVersions=true -DupdateWorkingCopyVersions=false

But this fails, with an error message warning me that I don't have commit rights into the $SVNROOT/project/tags/1.0 project-1.0 path (which is perfectly true---we don't allow commits into tags).

What am I doing wrong here, and why was Maven trying to commit something in the tag?

Update

Just to clarify: I am running this from the directory into which I've checked out the tag. The exact error I'm getting is the following:

[INFO] Executing: /bin/sh -c cd xxx && svn --non-interactive commit --file /tmp/maven-scm-28755080.commit --targets /tmp/maven-scm-535803351230252749-targets
[INFO] Working directory: xxx
org.apache.maven.shared.release.scm.ReleaseScmCommandException: Unable to commit files
Provider message:
The svn command failed.
Command output:
svn: Commit failed (details follow):
svn: 'pre-commit' hook failed with error output:
you do not have the rights to access this file: xxx/tags/xxx. 


        at org.apache.maven.shared.release.phase.ScmCommitPhase.checkin(ScmCommitPhase.java:133)
        at org.apache.maven.shared.release.phase.ScmCommitPhase.execute(ScmCommitPhase.java:109)
        at org.apache.maven.shared.release.DefaultReleaseManager.branch(DefaultReleaseManager.java:379)
        at org.apache.maven.shared.release.DefaultReleaseManager.branch(DefaultReleaseManager.java:350)
        at org.apache.maven.plugins.release.BranchReleaseMojo.execute(BranchReleaseMojo.java:133)
        at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:569)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:539)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:284)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
        at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
        at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
        at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
        at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Unable to commit files
Provider message:
The svn command failed.
Command output:
svn: Commit failed (details follow):
svn: 'pre-commit' hook failed with error output:
you do not have the rights to access this file: xxx/tags/xxx. 

Answer 1

Where did you execute that command mvn release:branch?

As mentioned in this thread:

What the plugin doco does specify is that the release:branch goal should be invoked from a checkout location with the revision/tag you want to branch from. (i.e. tags/<my_release_version>).

I used the following commandline to create a maintenance branch (branches/myapp-1.3.1) from an existing tag location (tags/myapp-1.3):

mvn release:branch -DbranchName=myapp-1.3.1 -DupdateBranchVersions=true
-DupdateWorkingCopyVersions=false

The -DupdateBranchVersions flag pertains to the versions in the pom.xml - not the scm versions.
If false, it will retain the same version as the tagged release;
if true, it will prompt for a version, defaulting to a snapshot of the tagged release, which may or may not be what you want.

See also this thread:

First you need to start with a working copy checked out from the Tag.
If the tag was created by the release plugin, the starting scm url should be correct, and point back to the tag.

Then use the plugin to crate the branch and switch the working copy to the branch.

An alternative is to manually:

• copy from the tag to a new branch
• switch the working copy to the new branch (or check out a working copy from the new branch)
• update the pom to use the new branch's url- commit the update to the pom

Answer 2

The commands you're running looks OK and strictly follow the example given in Create a Branch:

By default, the POM in the new branch keeps the same version as the local working copy, and the local POM is incremented to the next revision. If you want to update versions in the new branch and not in the working copy, run:

mvn release:branch -DbranchName=my-branch -DupdateBranchVersions=true -DupdateWorkingCopyVersions=false

Note: This can be useful if you want to create a branch from a tag

However, it seems that it's a 'pre-commit' hook that is failing and complaining. So I wonder:

• what you're doing in this hook
• what happens if you disable this hook temporarily