Build fails on Windows: UNC path is missing sharename: /\fakeSMTP-2.1-SNAPSHOT.jar

[Taschi120]

I'm trying to build FakeSMTP's docker image to use it for testing my web application. Sadly, the build fails with the following error:

[INFO] Copying C:\Users\Stephan\Documents\Programme\bulletin\FakeSMTP\target\fakeSMTP-2.1-SNAPSHOT.jar -> C:\Users\Stephan\Documents\Programme\bulletin\FakeSMTP\target\docker\fakeSMTP-2.1-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 36.687 s
[INFO] Finished at: 2017-11-12T17:38:07+01:00
[INFO] Final Memory: 28M/377M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal com.spotify:docker-maven-plugin:0.3.2:build (default-cli) on project fakesmtp: Exception caught: UNC path is missing sharename: /\fakeSMTP-2.1-SNAPSHOT.jar -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[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

The maven command I ran was as follows:

E:\apache-maven-3.5.2\bin\mvn package docker:build -DskipTests

[Taschi120]

Probably related to spotify/docker-maven-plugin#68, can maybe be fixed with a newer plugin version?

[Taschi120]

Using docker build . instead of the maven target works fine, though, so I won't try and troubleshoot this further. tldr: no maven dev or maven plugin dev ever tests their stuff on Windows, apparently.