in reply to Program arg interfering with redirecting STDERR to STDOUT

It's the shell in either environment that provides for the command line redirection syntax (2>&1). When you use backticks, the shell is bypassed unless you explicitly state it.

Something along these lines might work. 

my $shell = $^O eq 'MSWin32' 
    ? "$ENV{comspec} /c " 
    : "$ENV{shell} /?"; ## Bad guess

my @output = `$shell java yourprog 2>&1`;

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