Segfault in `StreamingMemoryReserveOrWait`

[pentschev]

There was a segfault in C++ tests last night, given this is coming from StreamingMemoryReserveOrWait which is new code, I'm gonna assume it has a high chance of being a legit bug.

Stack trace

2026-01-21T07:15:38.1431237Z [74dd5df98f6a:150314] *** Process received signal ***
2026-01-21T07:15:38.1431483Z [74dd5df98f6a:150314] Signal: Segmentation fault (11)
2026-01-21T07:15:38.1431754Z [74dd5df98f6a:150314] Signal code: Address not mapped (1)
2026-01-21T07:15:38.1431995Z [74dd5df98f6a:150314] Failing at address: (nil)
2026-01-21T07:15:38.1432444Z [       OK ] StreamingMemoryReserveOrWaitParams/StreamingMemoryReserveOrWait.ShutdownEarly/T2 (15 ms)
2026-01-21T07:15:38.1432872Z [       OK ] StreamingMemoryReserveOrWaitParams/StreamingMemoryReserveOrWait.CheckPriority/T8 (25 ms)
2026-01-21T07:15:38.1433682Z [74dd5df98f6a:150314] [ 0] /lib64/libpthread.so.0(+0x12990)[0x7c14792fe990]
2026-01-21T07:15:38.1434006Z [74dd5df98f6a:150314] [ 1] gtests/ucxx_tests(+0xe5a13)[0x582c29b03a13]
2026-01-21T07:15:38.1434473Z [ RUN      ] StreamingMemoryReserveOrWaitParams/StreamingMemoryReserveOrWait.RestartPeriodicTask/T1
2026-01-21T07:15:38.1434858Z [74dd5df98f6a:150314] [ 2] gtests/ucxx_tests(+0x200146)[0x582c29c1e146]
2026-01-21T07:15:38.1435137Z [74dd5df98f6a:150314] [ 3] gtests/ucxx_tests(+0x30de9e)[0x582c29d2be9e]
2026-01-21T07:15:38.1435414Z [74dd5df98f6a:150314] [ 4] gtests/ucxx_tests(+0x30e171)[0x582c29d2c171]
2026-01-21T07:15:38.1435693Z [74dd5df98f6a:150314] [ 5] gtests/ucxx_tests(+0x30e517)[0x582c29d2c517]
2026-01-21T07:15:38.1435973Z [74dd5df98f6a:150314] [ 6] gtests/ucxx_tests(+0x30e956)[0x582c29d2c956]
2026-01-21T07:15:38.1436252Z [74dd5df98f6a:150314] [ 7] gtests/ucxx_tests(+0x319fa3)[0x582c29d37fa3]
2026-01-21T07:15:38.1436540Z [74dd5df98f6a:150314] [ 8] gtests/ucxx_tests(+0x31a46d)[0x582c29d3846d]
2026-01-21T07:15:38.1436839Z [74dd5df98f6a:150314] [ 9] gtests/ucxx_tests(+0xace1d)[0x582c29acae1d]
2026-01-21T07:15:38.1437171Z [74dd5df98f6a:150314] [10] /lib64/libc.so.6(__libc_start_main+0xe5)[0x7c143a13e865]
2026-01-21T07:15:38.1437532Z [74dd5df98f6a:150314] [11] gtests/ucxx_tests(+0xad56e)[0x582c29acb56e]
2026-01-21T07:15:38.1437780Z [74dd5df98f6a:150314] *** End of error message ***

[madsbk]

Another hit: https://github.com/rapidsai/rapidsmpf/actions/runs/21397513115/job/61600224370?pr=825