[BUILD] Improve error message when bundled Maven wrapper fails

[hcavarsan]

What changes were proposed in this pull request?

Update build/make-distribution.sh to provide a error message when the bundled Maven wrapper (build/mvn) is not working, guiding users to specify an alternate Maven.

Why are the changes needed?

The bundled Maven wrapper can fail silently or produce unusable output, causing build failures like:

When the bundled Maven doesn't work correctly, the script fails without any helpful message, leaving users unsure how to proceed. This change adds a --version check with actionable error output:

• Validates Maven works before proceeding with the build
• If validation fails, exits with a clear message explaining how to use --mvn /path/to/mvn

Does this PR introduce any user-facing change?

No functional change. Error messaging is improved when Maven validation fails.

How was this patch tested?

Tested build script with broken bundled Maven, just confirm error message is displayed with instructions to specify alternate Maven path.

[pan3793]

fast-fail is an expected behavior, it's a dangerous fallback to system mvn without version checking.

you can use the system mvn by passing --mvn /path/of/mvn explicitly

[hcavarsan]

@pan3793 got it, makes sense. but the thing is… now when the bundled maven fails it just exits without any helpful message, so users don't know what to do. maybe just improving the error output would work?

if ! "$MVN" --version &>/dev/null; then
    echo -e "Could not execute Maven command: '$MVN'."
    echo "       Use --mvn /path/to/mvn to specify an alternate Maven."
    exit -1;
fi

[pan3793]

yeah, this sounds reasonable

[hcavarsan]

updated in b6fd49f

[hcavarsan]

now: