This exposes a PDL bug. That is PDL::srand/srandom has no effect and must call CORE::srand(N) instead for predictable output.
Uh, no: 
$ perl -Mblib -MPDL -E 'say $PDL::VERSION'
2.089_01

$ perl -Mblib -MPDL -E 'CORE::srand(4); say PDL->random'
0.437817146098168
$ perl -Mblib -MPDL -E 'CORE::srand(4); say PDL->random'
0.0596849513730282
$ perl -Mblib -MPDL -E 'CORE::srand(4); say PDL->random'
0.876085322091164
$ perl -Mblib -MPDL -E 'CORE::srand(4); say PDL->random'
0.0193676520337621

$ perl -Mblib -MPDL -E 'srandom(4); say PDL->random'
0.923230081572141
$ perl -Mblib -MPDL -E 'srandom(4); say PDL->random'
0.923230081572141
$ perl -Mblib -MPDL -E 'srandom(4); say PDL->random'
0.923230081572141
$ perl -Mblib -MPDL -E 'srandom(4); say PDL->random'
0.923230081572141

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In reply to Re^15: PDL and srand puzzle - PDL non-thread testing by etj
in thread PDL and srand puzzle by syphilis

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