Problem deploying to internal remote repository

[Ray Ward <wa...@gmail.com>]

I must be missing something obvious...   (I suspect the DEBUG line is
significant.)  Here's the error msg:

$ mvn -X deploy
...
[INFO] [deploy:deploy]
[DEBUG] not adding permissions to wagon connection
Uploading: scpexe://hostname/home/rward/tmp/path/to/pom/file
[INFO]
----------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO]
----------------------------------------------------------------------------
[INFO] Error deploying artifact: Error executing command for transfer

Exit code -1 - Permission denied (publickey,password,keyboard-interactive).

[DEBUG] Trace
org.apache.maven.lifecycle.LifecycleExecutionException: Error deploying
artifact: Error executing command for transfer
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(
DefaultLifecycleExecutor.java:556)
...

I have my username and password set up in ~/.m2/settings.xml:
<settings> ...
       <servers>
                <server>
                        <id>my-build-repository</id>
                        <username>username</username>
                        <password>xxxxxxxx</password>
                </server>
       </servers>
</settings>

 I have defined the repository and the wagon extension in the project's
pom.xml:
<project> ...
       <distributionManagement>
                <repository>
                        <id>my-build-repository</id>
                        <url>scpexe://hostname/home/rward/tmp</url>
                </repository>
       </distributionManagement>
...
       <build>
                <extensions>
                        <extension>
                                <groupId>org.apache.maven.wagon</groupId>
                                <artifactId>wagon-ssh</artifactId>
                                <version>1.0-alpha-7</version>
                        </extension>
                </extensions>
       </build>

 I can issue the scp from the command line with the same hostname, username
and password and it works:
$ scp ~/.m2/settings.xml rward@hostname:~/tmp/settings.xml
rward@hostname's password:
settings.xml              100% 8971    36.2MB/s   00:00

What do I have to do to get the permissions from the settings.xml to the
wagon connection?  Or is that a red herring?

TIA,

Ray