autopkgtest fails in Impish

https://autopkgtest.ubuntu.com/packages/o/opensaml/impish/amd64

https://autopkgtest.ubuntu.com/results/autopkgtest-impish/impish/amd64/o/opensaml/20210511_142913_c572c@/log.gz
...
make check-TESTS
make[1]: Entering directory '/tmp/autopkgtest.4GXJlH/build.9HD/src/samltest'
make[2]: Entering directory '/tmp/autopkgtest.4GXJlH/build.9HD/src/samltest'
../build-aux/test-driver: line 107: 5452 Killed "$@" > $log_file 2>&1
FAIL: samltest
=============================================
   opensaml 3.2.0: samltest/test-suite.log
=============================================

# TOTAL: 1
...

This test needs more RAM I can reproduce the failure locally in qemu with 1.5G RAM and it passes with 8G RAM.

Most likely the ppc64el tests would also pass with more RAM.