"I think if you want to change STDOUT globally for the debugger, some of the unicode flags in perlrun should do. (untested)"

I tried all of these:

$ perl -C -de1
...

$ perl -de1
...
  DB<1> use open OUT => qw{:encoding(UTF-8) :std}
...


$ perl -Mopen=OUT,:encoding\(UTF-8\),:std -de1
...
[download]

All gave the "Wide character ..." warning. All still printed "☺". There's probably other avenues of investigation for a global change: I didn't try anything further.

I think you need to append 'O' for "Output" to the '-C'

(my CMD-terminal has CP 850 so no emojis, sorry °)

C:\tmp>perl -we" binmode STDOUT, ':utf8'; print qq[\x{263A}] "
Ôÿ║
C:\tmp>perl -CO -wde0
...
main::(-e:1):   0
  DB<1> print "\x{263A}"
Ôÿ&#9553;
  DB<2>
[download]

UPDATE (codepage)

°) ah found the way to change the codepage

C:\tmp>CHCP 65001
Aktive Codepage: 65001.

C:\tmp>perl -CO -wde0

... yadda yadda ...

  DB<1> print "\x{263A}"
&#9786;
  DB<2>
[download]

PM's codeblocks are limited here², thats what I see ---> ☺ (sic)

update (pre tags)

²) or with <pre><tt> tags instead

C:\tmp>perl -CO -wde0

...

  DB<1> print "\x{263A}"
☺
  DB<2>

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}

I don't use the debugger (except in exercises like this) so it's more trial and error than knowledge for me. Anyway, I found the issue actually revolves around whether p or print is used.

$ perl -C -de1
...
  DB<1> print "\x{263A}"
☺
  DB<2> p "\x{263A}"
Wide character ...
...
☺

My guesswork here was based on a long-standing alias of mine:

$ alias perlu
alias perlu='perl -Mstrict -Mwarnings -Mautodie=:all -Mutf8 -C -E'
[download]

For example:

$ perlu 'say for $], "\x{263A}", "\x{ 263A }"'
5.036000
☺
☺

Update (checking for false positives):

$ perl -de1
...
  DB<1> print "\x{263A}"
Wide character ...
...
☺

$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -MCarp::Always -E
+'
[download]

$ perle 'say for $], "\x{263A}", "\x{ 263A }"'
5.036000
Wide character in say at -e line 1.
☺
Wide character in say at -e line 1.
☺

— Ken

Worked a treat on Mac.

~>perl -CO -wde0
# ...
main::(-e:1):	0
  DB<1> print "\x{263A}"
☺

Aha...

  DB<1> binmode STDOUT, ':utf8'; print "\x{263A}"                               
☺
  DB<2>   

Endlich erlungen. Vielen Dank....