Bear in mind that some regexp modifiers are mutually exclusive; for example /a which imposes ASCII semantics on the string being matches, and /l which imposes locale semantics on it. Thus s/foo/bar/miracles is a compile time error.

Here's a quick script to find allowable words...

#!/usr/bin/env perl

use v5.18;
open my $dict, "<", "/usr/share/dict/words";

while (<$dict>)
{
    next unless /^[msixpodualgcer]+$/;
    chomp;
    
    my $ok = do {
        my $testing = $_;
        local $_; # protection
        eval "s/foo/bar/$testing; 1";
    };
    
    say if $ok;
}
[download]

I rather like these ones:

• amigos
• carcass
• circus
• corridor
• crisscross
• gigolo
• girls
• idiom
• igloo
• macrocosm
• macroscopic
• mammograms
• microcosm
• microscopic
• orgasmic
• pompous
• program
• sarcasm
• scissors

Now to find a way to patch B::Deparse...