segfault when context switching in boost 1.76

[romange]

Sometimes I get segfault inside fiber library.

Below is a stacktrace that shows it

#0  boost::fibers::context::resume (this=0x0, lk=...) at libs/fiber/src/context.cpp:153
#1  0x00007ffff7fbabee in boost::fibers::scheduler::suspend (this=<optimized out>, lk=...) at libs/fiber/src/scheduler.cpp:314
#2  0x00007ffff7fb71dd in boost::fibers::context::suspend (this=this@entry=0xa6a4386ff00, lk=...) at libs/fiber/src/context.cpp:181
#3  0x00007ffff7fb851c in boost::fibers::wait_queue::suspend_and_wait (this=this@entry=0xa6a421609c8, lk=..., active_ctx=active_ctx@entry=0xa6a4386ff00) at libs/fiber/src/waker.cpp:21

[romange]

sorry, probably a problem with my scheduling algorithm.