How to make the maven release plugin work on widows with SSH outside of git-bash?

Question

I have a mvn release command that works on Windows inside a git-bash but as soon as I try in a cmd window, it fails.

The command is :

mvn -X -B -Dusername=git release:clean release:prepare release:perform

The error is the following :

[ERROR] Provider message:
[ERROR] The git-push command failed.
[ERROR] Command output:
[ERROR] [email protected]: Permission denied (publickey).
[ERROR] fatal: Could not read from remote repository.

My maven settings file is located as the default path ~/.m2/settings.xml and looks like:

<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 https://maven.apache.org/xsd/settings-1.2.0.xsd">
  <servers>
    <server>
        <id>github.com</id>
        <username>git</username>
        <privateKey>C:\Users\nicol\.ssh\id_ed25519</privateKey>
        <!-- also tried with ${user.home}/.ssh/id_ed25519 -->
        <passphrase>nico</passphrase>
    </server>
  </servers>
</settings>

I generated a private key using the command from the Github guide on deploy keys :

ssh-keygen -t ed25519 -C "[email protected]"

I uploaded the public key on the "Deploy keys" section of the Github repo.

Here's how the pom.xml looks like :

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.github.myusername</groupId>
    <artifactId>myrepo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.scm.id>github.com</project.scm.id>
    </properties>
    <scm>
        <connection>scm:git:https://github.com/myusername/myrepo.git</connection>
        <developerConnection>scm:git:ssh://[email protected]/myusername/myrepo.git</developerConnection>
        <url>https://github.com/myusername/myrepo</url>
        <tag>HEAD</tag>
    </scm>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-release-plugin</artifactId>
                <version>3.0.0-M5</version>
                <configuration>
                    <arguments>${arguments}</arguments>
                    <goals>install</goals>
                    <tagNameFormat>@{project.version}</tagNameFormat>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Below the version details :

• git version 2.34.1.windows.1
• java version "17.0.1" 2021-10-19 LTS
• Apache Maven 3.8.4

I tested with and without ssh agent on git-bash : it worked.

With cmd, I keep getting the same error.

What's going on ? How will I make it work on cmd ?

A bit of context: What I'm trying to build fails on ubuntu linux due to some tricky library issue and as it builds a Windows executable, it would probably make more sense to build on Windows. I plan to put the whole process into a Github workflow so I'd like it to validate it locally first. If the Github workflow/actions has an embedded Git-Bash, that could help too.

*** EDIT after @khmarbaise's comment ***

As I saw a mess in known_hosts file, here's what I did:

• deleted entries of known_hosts file
• generated public/private keys with command above
• uploaded public key in the "Deploy keys" section of the repo

Then, in a cmd prompt, the following scenario worked fine for me:

• git clone ssh://[email protected]/myusername/myrepo.git
• cd myrepo
• echo. >> README.md
• git add README.md
• git commit -a -m "added space at the end of the README"
• git push

Then I tried again the maven release command:

mvn -X -B -Dusername=git release:clean release:prepare release:perform

And had the error again:

The git-push command failed.
Command output:
[email protected]: Permission denied (publickey).
fatal: Could not read from remote repository.