Maven SCM plugin fails to do a scm:update after a scm:checkout with obscure error message

Question

I have configured a maven project to checkout a project using:

<scm>
    <developerConnection>scm:git:[email protected]:example/myproject.git</developerConnection>
</scm>

Using: mvn scm:checkout

The project checks out fine.

I would expect if scm:checkout works, scm:update should work too. But it doesn't. By running with the "-e" option (mvn -e scm:update) to get the full stack trace, it will show some obscure error message:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-scm-plugin:1.8.1:update (default-cli) on project mysampleproject: Command failed.The git-log command failed. -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-scm-plugin:1.8.1:update (default-cli) on project mysampleproject: Command failed.The git-log command failed.
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
    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:601)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.MojoExecutionException: Command failed.The git-log command failed.
    at org.apache.maven.scm.plugin.AbstractScmMojo.checkResult(AbstractScmMojo.java:439)
    at org.apache.maven.scm.plugin.UpdateMojo.execute(UpdateMojo.java:93)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
    ... 19 more
[ERROR] 
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

Now what should this error tell me ? Is this probably a bug in the Maven-scm-Plugin? Cause "git-log" does of course not even exist, its "git log" that would give you the Git log history.

Also the given help link will not help (from my point of view).