To set $! to a constant 1, you need to give the typeglob a reference to it: 

$ perl -Mwarnings -Mstrict -e'BEGIN { *! = \1; open my $fd, "< nonexis
+tent"; print "$!\n"; }'
1

[download]
It's notable that the typeglob assignment to constant destroys $!'s dual value magic: 
$ perl -e'$! = 1; print "$!\n"'
Operation not permitted

[download]

I don't know whether the segfault is justified or a bug or simply undefined behavior. Just setting *@ = \1 (or 1) does not fire the segfault. I expect that die has some eval-like tendencies.

After Compline,
Zaxo

In reply to Re: eval segfaults when $@ isn't writable by Zaxo
in thread eval segfaults when $@ isn't writable by Hue-Bond

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