I'll post this to the porters list, as using "<:encoding(utf-8)" does not fail.

update: This was fixed in version 5.13.10:

  41    0.00918   0.010   0.000 FAIL base/tperl5.11.3
  42    0.01080   0.010   0.000 FAIL base/perl5.11.4
  43    0.00798   0.000   0.000 FAIL base/tperl5.11.4
  44    0.00445   0.000   0.000 FAIL base/perl5.11.5
  45    0.01272   0.010   0.010 FAIL base/tperl5.11.5
  46    0.00596   0.010   0.000 FAIL base/perl5.12.0
  47    0.00458   0.000   0.000 FAIL base/tperl5.12.0
  48    0.00418   0.010   0.000 FAIL base/perl5.12.1
  49    0.00460   0.000   0.000 FAIL base/tperl5.12.1
  50    0.00399   0.000   0.000 FAIL base/perl5.12.2
  51    0.00468   0.000   0.000 FAIL base/tperl5.12.2
  52    0.00394   0.010   0.000 FAIL base/perl5.12.3
  53    0.00475   0.000   0.000 FAIL base/tperl5.12.3
  54    0.00425   0.000   0.010 FAIL base/perl5.12.4
  55    0.00952   0.000   0.000 FAIL base/tperl5.12.4
  56    0.00676   0.000   0.010 FAIL base/perl5.13.0
  57    0.00692   0.000   0.000 FAIL base/tperl5.13.0
  58    0.00473   0.000   0.000 FAIL base/perl5.13.1
  59    0.00498   0.010   0.000 FAIL base/tperl5.13.1
  60    0.00446   0.000   0.000 FAIL base/perl5.13.2
  61    0.00493   0.010   0.000 FAIL base/tperl5.13.2
  62    0.00676   0.000   0.000 FAIL base/perl5.13.3
  63    0.00482   0.000   0.000 FAIL base/tperl5.13.3
  64    0.00447   0.000   0.000 FAIL base/perl5.13.4
  65    0.00491   0.010   0.000 FAIL base/tperl5.13.4
  66    0.00452   0.000   0.000 FAIL base/perl5.13.5
  67    0.00540   0.000   0.000 FAIL base/tperl5.13.5
  68    0.00401   0.000   0.010 FAIL base/perl5.13.6
  69    0.00479   0.000   0.000 FAIL base/tperl5.13.6
  70    0.00408   0.000   0.000 FAIL base/perl5.13.7
  71    0.00519   0.000   0.000 FAIL base/tperl5.13.7
  72    0.00443   0.000   0.000 FAIL base/perl5.13.8
  73    0.00508   0.010   0.000 FAIL base/tperl5.13.8
  74    0.00458   0.000   0.000 FAIL base/perl5.13.9
  75    0.00483   0.010   0.010 FAIL base/tperl5.13.9
  76    0.00448   0.000   0.000 PASS base/perl5.13.10
  77    0.00503   0.000   0.000 PASS base/tperl5.13.10
  78    0.00434   0.010   0.000 PASS base/perl5.13.11
  79    0.00508   0.000   0.000 PASS base/tperl5.13.11
  80    0.00435   0.000   0.000 PASS base/perl5.14.0
  81    0.00459   0.000   0.010 PASS base/tperl5.14.0
  82    0.00493   0.000   0.000 PASS base/perl5.14.1
  83    0.01190   0.000   0.000 PASS base/tperl5.14.1
  84    0.00434   0.000   0.000 PASS base/perl5.15.0
  85    0.00484   0.000   0.000 PASS base/tperl5.15.0
  86    0.00447   0.010   0.000 PASS base/perl5.15.1
  87    0.00484   0.010   0.000 PASS base/tperl5.15.1
  88    0.00455   0.000   0.000 PASS base/perl5.15.2
  89    0.00501   0.000   0.010 PASS base/tperl5.15.2
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