also hash key randomness can be influenced (I don mean this is a wise thing to do..) by ENV vars, specifically PERL_PERTURB_KEYS and PERL_HASH_SEED

perl -v

This is perl 5, version 26, subversion 0 (v5.26.0) built for MSWin32-x
+64-multi-thread

perl -wMstrict -le "for (1 .. 8) {my @k = keys %{ { map { $_ => 1 } 0 
+.. 8 } };print qq{@k};}"

2 8 5 3 0 1 4 6 7
2 0 8 5 3 1 6 4 7
2 4 7 6 1 3 8 5 0
1 4 7 6 0 8 5 3 2
2 0 8 5 3 1 7 6 4
4 7 6 1 3 5 8 0 2
3 8 5 0 6 4 7 1 2
0 5 8 3 1 6 4 7 2


set PERL_PERTURB_KEYS=0
set PERL_HASH_SEED=0x0


perl -wMstrict -le "for (1 .. 8) {my @k = keys %{ { map { $_ => 1 } 0 
+.. 8 } };print qq{@k};}"

6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4
6 7 5 2 3 1 0 8 4


set PERL_PERTURB_KEYS=
set PERL_HASH_SEED=

perl -wMstrict -le "for (1 .. 8) {my @k = keys %{ { map { $_ => 1 } 0 
+.. 8 } };print qq{@k};}"

2 8 4 1 6 0 3 5 7
3 5 7 8 2 4 1 6 0
5 3 7 4 1 2 8 0 6
4 1 2 8 0 6 5 3 7
7 3 5 6 0 2 8 4 1
5 3 7 1 4 2 8 0 6
7 5 3 0 6 4 1 8 2
7 3 5 6 0 8 2 1 4
[download]

see also PERL_HASH_SEED and PERL_PERTURB_KEYS both on perlrun and Algorithmic-Complexity-Attacks and order of hash and setting PERL_PERTURB_KEYS & PERL_HASH_SEED in a perl file

L*