testIgnoreSigterm fails on Buildkite

[wilzbach]

[INFO] Running test tests/vibe.core.process.d
--
  | + dub --temp-build --compiler=dmd --single tests/vibe.core.process.d
  | Performing "debug" build using dmd for x86_64.
  | taggedalgebraic 0.11.7: target for configuration "library" is up to date.
  | eventcore 0.8.48: target for configuration "epoll" is up to date.
  | stdx-allocator 2.77.5: target for configuration "library" is up to date.
  | vibe-core 1.7.0: target for configuration "epoll" is up to date.
  | test ~master: building configuration "application"...
  | Linking...
  | To force a rebuild of up-to-date targets, run again with --force.
  | Running ../tmp/.dub/build/test-~master/application-debug-linux.posix-x86_64-dmd_2089-CCE0B336259E1CF00226678E62394B31/test
  | [main(BDds) INF] Running test testEcho...
  | [main(9qP+) INF] Running test testCat...
  | [main(Jea+) INF] Running test testStderr...
  | [main(Vvlk) INF] Running test testRandomDeath...
  | [main(UsqA) INF] Running test testIgnoreSigterm...
  | core.exception.AssertError@tests/vibe.core.process.d(147): Assertion failure
  | ----------------
  | ??:? _d_assertp [0x67a295]
  | tests/vibe.core.process.d:147 void test.testIgnoreSigterm() [0x5c27ac]
  | tests/vibe.core.process.d:204 nothrow void test.main().__lambda1().__lambda5() [0x5c31fa]
  | source/vibe/core/task.d:652 nothrow void vibe.core.task.TaskFuncInfo.set!(void function() nothrow*).set(ref void function() nothrow*).callDelegate(ref vibe.core.task.TaskFuncInfo) [0x5d7676]
  | source/vibe/core/task.d:673 void vibe.core.task.TaskFuncInfo.call() [0x5f618d]
  | source/vibe/core/task.d:399 nothrow void vibe.core.task.TaskFiber.run() [0x5f53b0]
  | ??:? void core.thread.fiber.Fiber.run() [0x6ba441]
  | ??:? fiber_entryPoint [0x6ba326]
  | ??:? [0xffffffffffffffff]
  | Program exited with code -6

See e.g.