yosys autopkgtest time out on ppc64el, same test complete during build

I am trying to get an updated edition of yosys into testing, but have
run into a confusing problem a I hope someone can help to solve.

As can be seen on <URL: https://tracker.debian.org/pkg/yosys >, the
package build just fine on little endian machines, and even seem to
build just fine on most big endian machines (despite what I suspect is a
segfaults in the abc subsystem).  The autopkgtest check on ppc64el on
the other hand fail with a timeout after around 10000 seconds, which is
rather strange, as the exact same set of tests completed successfully
when the package was built.

Anyone got a clue how to avoid the timeout?

Note, sparc64 crashes due to alighment issues with memory access, see
<URL: https://github.com/berkeley-abc/abc/pull/504 > for my incomplete
draft for fixing these.  Could it be that misalliged memory accesses
slow down ppc64el so much that the tests time out?

PS: I am not a subscriber, so please keep me on CC.