Parser rejects valid `return sort map` in Mojolicious 9.49

The issue is in the parser's diagnostic logic for the return statement, likely in the file handling the commit d4ebdd9b4. Start by examining the parser's grammar for return and the diagnostic for indirect map/grep arguments. The failing code is in Mojo/Loader.pm line 37. Write a test that reproduces the error with return sort map ... and ensure the diagnostic only triggers for return map/grep ... without an intervening list operator like sort.

Summary

PerlOnJava cannot load Mojolicious 9.49 because the parser rejects valid Perl in Mojo::Loader::find_packages:

return sort map { /^(.+)::$/ ? "${ns}::$1" : () } keys %{"${ns}::"};

The error is:

Missing comma after first argument to return

This causes WebService-Rollbar-Notifier 1.002011 to fail its load tests.

Reproduction

Archived CPAN run: 20260924-085657-82687

Target distribution: WebService-Rollbar-Notifier-1.002011

The target fails 2 of 3 tests in t/00-load.t while loading Mojo::UserAgent and WebService::Rollbar::Notifier. The failure reproduces on both the JVM and interpreter backends.

A minimal load reproducer is:

PERL5LIB=<Mojolicious-lib> ./jperl -MMojo::Loader -e 'print "loaded\\n"'
PERL5LIB=<Mojolicious-lib> ./jperl --interpreter -MMojo::Loader -e 'print "loaded\\n"'

Both report the diagnostic at Mojo/Loader.pm line 37. System Perl loads the same module successfully.

Expected behavior

Mojo::Loader should compile successfully. System Perl passes Mojolicious 9.49's complete suite (4,194 tests) and the Rollbar distribution's 5 tests.

Suspected cause

The regression appears related to the indirect return map/grep diagnostic added in commit d4ebdd9b4 (fix: diagnose indirect map arguments to return). The diagnostic logic appears to treat return sort map ... as an invalid indirect map argument, although the intervening sort makes this valid Perl.

Requested fix

Restrict the diagnostic to actual indirect return NAME map/grep ... forms while preserving valid list operators such as return sort map .... Add a focused regression test for the Mojolicious expression and retain the existing diagnostic coverage.