panda build breakage

==> Bootstrapping Panda
Unable to parse expression in string; couldn't find final \"
  in any FAILGOAL at src/stage2/QRegex.nqp:1084
  in regex string at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:25
  in regex pair at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:7
  in regex pairlist at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:6
  in regex object at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:5
  in regex value:sym<object> at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:21
  in any !protoregex at src/stage2/QRegex.nqp:746
  in regex value at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:11
  in regex arraylist at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:9
  in regex array at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:8
  in regex TOP at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny/Grammar.pm:4
  in method parse at src/gen/CORE.setting:10788
  in sub from-json at /opt/perl6/panda/ext/JSON__Tiny/lib/JSON/Tiny.pm:50
  in submethod BUILD at /opt/perl6/panda/lib/Panda/Ecosystem.pm:62
  in method BUILDALL at src/gen/CORE.setting:759
  in method bless at src/gen/CORE.setting:743
  in method new at src/gen/CORE.setting:728
  in method new at /opt/perl6/panda/lib/Panda.pm:20
  in block  at bin/panda:108