exception

Malformed parameter
   at SETTING::src/core.c/Exception.pm6:65  (/Users/tonyo/.local/share/perl6/runtime/CORE.c.setting.moarvm:throw)
 from src/Raku/ast/resolver.rakumod:894  (/Users/tonyo/.local/share/perl6/lib/Perl6/BOOTSTRAP/v6c.moarvm:panic)
 from src/Raku/Grammar.nqp:338  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:typed_panic)
 from src/Raku/Grammar.nqp:290  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:malformed)
 from src/Raku/Grammar.nqp:2969  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:signature)
 from src/Raku/Grammar.nqp:2505  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:method_def)
 from src/Raku/Grammar.nqp:514  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:key-origin)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:routine_declarator:sym<submethod>)
 from NQP::src/QRegex/Cursor.nqp:645  (/Users/tonyo/.local/share/nqp/lib/QRegex.moarvm:!protoregex)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:routine_declarator)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:term:sym<routine_declarator>)
 from NQP::src/QRegex/Cursor.nqp:645  (/Users/tonyo/.local/share/nqp/lib/QRegex.moarvm:!protoregex)
 from <unknown>:1  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:term)
 from src/Raku/Grammar.nqp:1732  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:termish)
 from NQP::src/HLL/Grammar.nqp:418  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:EXPR)
 from src/Raku/Grammar.nqp:1094  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:EXPR)
 from src/Raku/Grammar.nqp:685  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:statement)
 from src/Raku/Grammar.nqp:514  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:key-origin)
 from src/Raku/Grammar.nqp:648  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:statementlist)
 from src/Raku/Grammar.nqp:514  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:key-origin)
 from src/Raku/Grammar.nqp:766  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:blockoid)
 from src/Raku/Grammar.nqp:749  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:block)
 from src/Raku/Grammar.nqp:2247  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:package_def)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:package_declarator:sym<class>)
 from NQP::src/QRegex/Cursor.nqp:647  (/Users/tonyo/.local/share/nqp/lib/QRegex.moarvm:!protoregex)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:package_declarator)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:term:sym<package_declarator>)
 from NQP::src/QRegex/Cursor.nqp:647  (/Users/tonyo/.local/share/nqp/lib/QRegex.moarvm:!protoregex)
 from <unknown>:1  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:term)
 from src/Raku/Grammar.nqp:1732  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:termish)
 from NQP::src/HLL/Grammar.nqp:418  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:EXPR)
 from src/Raku/Grammar.nqp:1094  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:EXPR)
 from src/Raku/Grammar.nqp:685  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:statement)
 from src/Raku/Grammar.nqp:514  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:key-origin)
 from src/Raku/Grammar.nqp:648  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:statementlist)
 from NQP::src/HLL/Grammar.nqp:646  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:LANG)
 from src/Raku/Grammar.nqp:632  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:FOREIGN_LANG)
 from src/Raku/Grammar.nqp:514  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:key-origin)
 from src/Raku/Grammar.nqp:610  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:comp_unit)
 from src/Raku/Grammar.nqp:584  (/Users/tonyo/.local/share/perl6/lib/Raku/Grammar.moarvm:TOP)
 from NQP::src/QRegex/Cursor.nqp:1223  (/Users/tonyo/.local/share/nqp/lib/QRegex.moarvm:parse)
 from NQP::src/HLL/Compiler.nqp:553  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:parse)
 from NQP::src/HLL/Compiler.nqp:465  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:execute_stage)
 from NQP::src/HLL/Compiler.nqp:501  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:run)
 from NQP::src/HLL/Compiler.nqp:504  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:)
 from NQP::src/HLL/Compiler.nqp:496  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:compile)
 from SETTING::src/core.c/core_epilogue.pm6:167  (/Users/tonyo/.local/share/perl6/runtime/CORE.c.setting.moarvm:AST)
 from /Users/tonyo/d/watson/lib/Watson.rakumod (Watson):15  (/Users/tonyo/d/watson/.precomp/6A220E60ADF2B417B8E59C10323CE0606E3004B9/8B/8BD740BA1996A86418BBB334FCF96A37A582107C:get-pod)
 from /Users/tonyo/d/watson/bin/watson:5  (<ephemeral file>:<unit>)
 from NQP::src/HLL/Compiler.nqp:196  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:eval)
 from NQP::src/HLL/Compiler.nqp:441  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:evalfiles)
 from NQP::src/HLL/Compiler.nqp:364  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:command_eval)
 from src/Perl6/Compiler.nqp:233  (/Users/tonyo/.local/share/perl6/lib/Perl6/Compiler.moarvm:command_eval)
 from NQP::src/HLL/Compiler.nqp:289  (/Users/tonyo/.local/share/nqp/lib/NQPHLL.moarvm:command_line)
 from src/main.nqp:81  (/Users/tonyo/.local/share/perl6/runtime/perl6.moarvm:MAIN)
 from src/main.nqp:63  (/Users/tonyo/.local/share/perl6/runtime/perl6.moarvm:<mainline>)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/runtime/perl6.moarvm:<main>)
 from <unknown>:1  (/Users/tonyo/.local/share/perl6/runtime/perl6.moarvm:<entry>)

x.raku

unit module watson;

use experimental :rakuast;

sub get-pod(Str:D $module --> Str) is export {
  my $spec  = CompUnit::DependencySpecification.new(:short-name($module));
  my @dists = |$*REPO.repo-chain
                     .map(*.resolve($spec))
                     .grep({ .defined && +@($_) })
                     ;#.sort(...);

  #warn 'multiple candidates found' if +@curi-dists > 1;
  die 'no candidates found' if +@dists == 0;
  my $dist = @dists[0];
  "{$dist.repo.prefix}/sources/{$dist.repo-id}".IO.slurp.AST;
}