[perl #130653] The Proc from run() and :out seems always to report exitcode 0

[brian d foy]

# New Ticket Created by  "brian d foy" 
# Please include the string:  [perl #130653]
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# <URL: https://rt.perl.org/Ticket/Display.html?id=130653 >


It seems that the exit value that a Proc object returns isn't
always what I expect. In the calls where I specify :out, the
exit code seems to always be 0.

    use Test;

    my $program = '/usr/bin/false'; # maybe yours is different

    ok $program.IO.e, 'program exists';

    subtest {
        my $proc = run $program;
        is $proc.exitcode, 1, 'No arguments';
        }, 'run with no arguments';

    subtest {
        my $proc = run $program, :out;
        is $proc.exitcode, 1, 'Output specified, check exit before
read'; # is it finished running?
        $proc.out.slurp-rest;
        }, 'run with :out argument, read after';

    subtest {
        my $proc = run $program, :out;
        $proc.out.slurp-rest;
        is $proc.exitcode, 1, 'Output, check exit after read';
        }, 'run with :out argument, read first';

    subtest {
        my $null = $*SPEC.devnull.IO.open;
        # the program shouldn't compile and perl6 should return 1
        my $proc = run $*EXECUTABLE, '-c', $program, :out, :err($null);
        $proc.out.slurp-rest;
        is $proc.exitcode, 1, 'Output, check exit after read';
        }, 'compile check, read first';

    done-testing();

And, the output:

    ok 1 - program exists
        ok 1 - No arguments
        1..1
    ok 2 - run with no arguments
        not ok 1 - Output specified, check exit before read
        1..1
    not ok 3 - run with :out argument, read after
        not ok 1 - Output, check exit after read
        1..1
    not ok 4 - run with :out argument, read first
        not ok 1 - Output, check exit after read
        1..1
    not ok 5 - run with :out argument, read first
    1..5

        # Failed test 'Output specified, check exit before read'
        # at /Users/brian/Desktop/false.p6 line 18
        # expected: '1'
        #      got: '0'
        # Looks like you failed 1 test of 1

    # Failed test 'run with :out argument, read after'
    # at /Users/brian/Desktop/false.p6 line 16

        # Failed test 'Output, check exit after read'
        # at /Users/brian/Desktop/false.p6 line 25
        # expected: '1'
        #      got: '0'
        # Looks like you failed 1 test of 1

    # Failed test 'run with :out argument, read first'
    # at /Users/brian/Desktop/false.p6 line 22

        # Failed test 'Output, check exit after read'
        # at /Users/brian/Desktop/false.p6 line 33
        # expected: '1'
        #      got: '0'
        # Looks like you failed 1 test of 1

    # Failed test 'run with :out argument, read first'
    # at /Users/brian/Desktop/false.p6 line 28
    # Looks like you failed 3 tests of 5

The details:

$ perl6 -v && uname -a
This is Rakudo version 2016.11 built on MoarVM version 2016.11
implementing Perl 6.c.
Darwin macpro.local 14.5.0 Darwin Kernel Version 14.5.0