Is negative lookbehind behaving here?

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I want to match something anywhere but at the end of a string in one
example, or anywhere but at the start of a string in another example. The
"except at start" one has me stumped. Not sure if it's me or if I've
tickled a bug.

perl6 --version
This is Rakudo Star version 2018.01 built on MoarVM version 2018.01
implementing Perl 6.c.

# Match all but at end- this works as I like
> 'abcd' ~~ m/.+<!before $>/
=EF=BD=A2abc=EF=BD=A3

# Match all but at start- this puzzles me, 'a' is after the start of string
but still matches
> 'abcd' ~~ m/<!after ^>.+/
=EF=BD=A2abcd=EF=BD=A3

# This is a workaround
> 'abcd' ~~ m/<!before ^>.+/
=EF=BD=A2bcd=EF=BD=A3

Using a perl5 debugger session, roughly translated negative
lookbehind/lookahead work as I expect.

  DB<1> p 'abcd' =3D~ /(.+(?!$))/
abc
  DB<2> p 'abcd' =3D~ /((?<!^).*)/
bcd

-y

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<div dir=3D"ltr"><div>I want to match something anywhere but at the end of =
a string in one example, or anywhere but at the start of a string in anothe=
r example. The &quot;except at start&quot; one has me stumped. Not sure if =
it&#39;s me or if I&#39;ve tickled a bug.<br></div><div><br>perl6 --version=
<br>This is Rakudo Star version 2018.01 built on MoarVM version 2018.01<br>=
implementing Perl 6.c.<br><br></div><div># Match all but at end- this works=
 as I like<br></div><div>&gt; &#39;abcd&#39; ~~ m/.+&lt;!before $&gt;/<br>=
=EF=BD=A2abc=EF=BD=A3<br><br></div><div># Match all but at start- this puzz=
les me, &#39;a&#39; is after the start of string but still matches<br></div=
><div>&gt; &#39;abcd&#39; ~~ m/&lt;!after ^&gt;.+/<br>=EF=BD=A2abcd=EF=BD=
=A3<br><br></div><div># This is a workaround<br>&gt; &#39;abcd&#39; ~~ m/&l=
t;!before ^&gt;.+/<br>=EF=BD=A2bcd=EF=BD=A3<br></div><div><br>Using a perl5=
 debugger session, roughly translated negative lookbehind/lookahead work as=
 I expect.<br><br>=C2=A0 DB&lt;1&gt; p &#39;abcd&#39; =3D~ /(.+(?!$))/<br>a=
bc<br>=C2=A0 DB&lt;2&gt; p &#39;abcd&#39; =3D~ /((?&lt;!^).*)/<br>bcd<br><b=
r clear=3D"all"><div><div class=3D"gmail_signature">-y<br></div></div>
</div></div>

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