The background environment is confirm stable with success build via
make BOARDS=custom_board PREBUILT=focal.arm.2.7.0_2021_11_17.tar.gz
Which the PYNQ/build.sh script is masked after line 105 with no building Arduino stuff etc.
The question here is make will result error::
Stack:
/lib/x86_64-linux-gnu/libc.so.6(+0x3ef10) [0x7f0c85dcaf10]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(sta::Search::deratedDelays(sta::Vertex*, sta::TimingArc*, sta::Edge*, bool, bool const*, sta::DelayVsta)+0xc0) [0x7f0c48542ca0]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(sta::VisitContext::fetchDeratedDelays(sta::Vertex, sta::TimingArc*, sta::Edge*, bool, bool const*)+0x75) [0x7f0c48542e25]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(sta::SearchPathVisitor::visitFromPaths(sta::Vertex*, sta::Tag*, sta::TransRiseFall const*, sta::Edge*, sta::TimingArc*, sta::Vertex*, sta::TransRiseFall const*, sta::VisitContext&)+0x18f) [0x7f0c4857c9df]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(sta::PathVisitor::visitEdge(sta::Pin const*, sta::Vertex*, sta::Edge*, sta::Pin const*, sta::Vertex*)+0x37d) [0x7f0c4856569d]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(+0x48a66f) [0x7f0c4853d66f]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(sta::ArrivalVisitor::visit(sta::Vertex*)+0x126) [0x7f0c48578b86]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(void sta::forEachBeginNoLock<sta::BfsListIterator, sta::VertexVisitor, sta::Vertex*>(void*)+0x26) [0x7f0c484e1e06]
/home/pynq/xilinx/Vivado/2020.2/lib/lnx64.o/librdi_psta.so(sta::ThreadWorker::threadBegin(void*)+0x6c) [0x7f0c485c632c]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x76db) [0x7f0c85b746db]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x3f) [0x7f0c85ead61f]