t/ack-pager.t fails on Cygwin

[tzccinct]

The test t/ack-pager.t is skipped when IO::Pty is not installed, but when it is not skipped, it fails on Cygwin.
http://www.cpantesters.org/cpan/report/9e18340c-72c4-1014-ace7-3a9e76d8a230

    #   Failed test 'PAGER'
    #   at t/Util.pm line 585.
    #     Structures begin differing at:
    #          $got->[0] = '/usr/bin/env: `perl': No such file or directory'
    #     $expected->[0] = 't/text/raven.txt'
    # actual[
    #   '/usr/bin/env: `perl\': No such file or directory'
    # ]
    # expected[
    #   't/text/raven.txt',
    #   '55:    Quoth the Raven, "Nevermore."',
    #   '62:    With such name as "Nevermore."',
    #   '69:    Then the bird said, "Nevermore."',
    #   '76:    Of \'Never -- nevermore.\'',
    #   '83:    Meant in croaking "Nevermore."',
    #   '90:    She shall press, ah, nevermore!',
    #   '97:    Quoth the Raven, "Nevermore."',
    #   '104:    Quoth the Raven, "Nevermore."',
    #   '111:    Quoth the Raven, "Nevermore."',
    #   '118:    Quoth the Raven, "Nevermore."',
    #   '125:    Shall be lifted--nevermore!'
    # ]
    # Looks like you failed 1 test of 1.

It is because PATH environment variable is deleted from %ENV in t/Util.pm prep_environment(), then t/test-pager, whose shebang is #!/usr/bin/env perl, is tried to open. Deleting PATH has been introduced in ack 2.13_01 for taint mode (perl's -T option). The most apparent patch is not to delete PATH from %ENV, but I'm not sure if it's a correct approach.

[petdance]

Thanks for the report and the investigation.