[regression] Maven4 unable to pass settings path on Windows

[hohwille]

Affected version

4.0.0-rc-5

Bug description

Updating to Maven4 breaks my usage scenario:

$ echo $MAVEN_ARGS
-s D:\projects\mmm\conf\mvn\settings.xml -Dsettings.security=D:\projects\mmm\conf\mvn\settings-security.xml
$ mvn -v
[ERROR] Error executing Maven.
[ERROR] The specified user settings file does not exist: D:\projects\mmm\projectsmmmconfmvnsettings.xml

To me it looks as if maven4 does some transformation with backslashes in path's.
Maybe also the wrapper script calling maven via Java is causing this effect.
I diffed the mvn wrapper script and found that in 3.9.9 it was containing this relevant block that was removed in maven 4.0:

# For MinGW, ensure paths are in Unix format before anything is touched
if $mingw ; then
  [ -n "$MAVEN_HOME" ] &&
    MAVEN_HOME=`(cd "$MAVEN_HOME"; pwd)`
  [ -n "$JAVA_HOME" ] &&
    JAVA_HOME=`(cd "$JAVA_HOME"; pwd)`
  # TODO classpath?
fi

UPDATE: I do not believe this is related to the bug. I rather expect the bug to be in the Java code.

When I downgrade to maven 3.x it works again:

$ mvn -v
WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by org.fusesource.jansi.internal.JansiLoader in an unnamed module (file:/D:/projects/mmm/software/mvn/lib/jansi-2.4.1.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

Apache Maven 3.9.9 (8e8579a9e76f7d015ee5ec7bfcdc97d260186937)
Maven home: D:\projects\mmm\software\mvn
Java version: 25, vendor: Eclipse Adoptium, runtime: D:\projects\mmm\software\java
Default locale: en_US, platform encoding: UTF-8
OS name: "windows 11", version: "10.0", arch: "amd64", family: "windows"

[hohwille]

Please note that when setting e.g. MAVEN_ARGS on Windows, I expect this to work in different environments:

• MS DOS (aka CMD)
• Git-Bash
• Maybe even in cygwin (see [MNG-8056] Parameter '-f' & '-s' fails with absolute paths on Cygwin #10810 that seems related)

I therefore have to specify the PATH syntax in Windows style with drive letter followed by colon (and using backslashes).

[hohwille]

If I test the same in CMD terminal on Windows it is working:

D:\projects\mmm>echo %MAVEN_ARGS%
-s D:\projects\mmm\conf\mvn\settings.xml -Dsettings.security=D:\\projects\\mmm\\conf\\mvn\\settings-security.xml
D:\projects\mmm>mvn -v
Apache Maven 4.0.0-rc-5 (fb3ecaef88106acb40467a450248dfdbd75f3b35)
Maven home: D:\projects\mmm\software\mvn
Java version: 25, vendor: Eclipse Adoptium, runtime: D:\projects\mmm\software\java
Default locale: en_US, platform encoding: UTF-8
OS name: "windows 11", version: "10.0", arch: "amd64", family: "winnt"

[gnodet]

Note that mvnd does translate (only the current directory) when running in Cygwin, see https://github.com/apache/maven-mvnd/blob/7b309de9ab8e8ed4e65cb43f59c9a3e22edc69e0/daemon/src/main/java/org/mvndaemon/mvnd/cli/EnvHelper.java#L97-L109

[hohwille]

Note that mvnd does translate (only the current directory) when running in Cygwin, see https://github.com/apache/maven-mvnd/blob/7b309de9ab8e8ed4e65cb43f59c9a3e22edc69e0/daemon/src/main/java/org/mvndaemon/mvnd/cli/EnvHelper.java#L97-L109

Nice feature. However, I stopped using cygwin and only use git-bash that is based on MINGW.

• Windows C:\Users
• git-bas: /c/users
• cygwin: /cygdrive/c/users

I also implemented such support in my product IDEasy:
https://github.com/devonfw/IDEasy/blob/main/cli/src/test/java/com/devonfw/tools/ide/os/WindowsPathSyntaxTest.java

It already supports mvn and mvnw among gradle, gradlew, and tons of other tools.
I am planning support for mvnd soon.

BTW: Besides this product flavour sneaking in with /cygdrive I especially dislike that cygwin creates its own users home directory so you have two different home directories as a Windows user what IMHO causes a lot of trouble and confusion.
However cygwin is still great if you want to install packages and special GNU Linux software without virtualisation (WSL2 or even a full VM).

[hohwille]

@khmarbaise I would even create a PR to fix such issue myself.
Do you happen to have some instructions how to setup and debug Maven directly from its source-code?
I always failed at this point to deep dive into maven core.
Implementing and debugging Mojos is what I have done already a lot...
So if you have a guess how to start, I am happy to support by creating a PR.

[hohwille]

This bug seems to be slightly related to #10834

[hohwille]

Some first traces browsing the source-code:

• maven/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/BaseParser.java

  Lines 219 to 221 in f93b562

  	options.altUserSettings()
  	.ifPresent(userSettings ->
  	failIfFileNotExists(context, userSettings, "The specified user settings file does not exist"));

• maven/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/BaseParser.java

  Lines 247 to 253 in f93b562

  	protected void failIfFileNotExists(LocalContext context, String fileName, String message) {
  	Path path = context.cwd.resolve(fileName);
  	if (!Files.isRegularFile(path)) {
  	context.parsingFailed = true;
  	context.parserRequest.logger().error(message + ": " + path);
  	}
  	}

• maven/api/maven-api-cli/src/main/java/org/apache/maven/api/cli/Options.java

  Line 127 in f93b562

  Optional<String> altUserSettings();

• maven/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/CommonsCliOptions.java

  Lines 142 to 147 in f93b562

  	public Optional<String> altUserSettings() {
  	if (commandLine.hasOption(CLIManager.ALTERNATE_USER_SETTINGS)) {
  	return Optional.of(commandLine.getOptionValue(CLIManager.ALTERNATE_USER_SETTINGS));
  	}
  	return Optional.empty();
  	}