Package:  pari

Version:  [2,7,0]

gp > polresultant(1 + x*z^2, 1 + y*z^6, z)

  ***   at top-level: polresultant(1+x*z^2

  ***                 ^--------------------

  *** polresultant: bug in gerepile, significant pointers lost, please report.

Expected output was

(x^3 - y)^2

I am running Windows 7 on a core i7.

This bug does not occur if y*z^6 is changed to y*z^7 (or any odd exponent).

It does not occur with polresultant(1 + x*z^2, 1 + x*z^6, z)

Best wishes

Victor