Here's a little more info:

jump_fcontext ()

libs/context/src/asm/jump_x86_64_sysv_elf_gas.S:45

45 popq %r12 /* restrore R12 */

rsp is 0x0, because rdi is 0x0, which was supposed to point to the context data.  Attempting to add printf to the 8 jump_fcontext call sites.