Intermittent make check test failures

With a local build of today's master branch, make check fails with this at the end of the log:

The following tests FAILED:
    720 - reverse_alarm-no-syscallbuf (Failed)
    1452 - checkpoint_async_signal_syscalls_1000-32-no-syscallbuf (Failed)
    1501 - reverse_alarm-32 (Failed)

I haven't tried to build rr for a while on this computer so I am not implying that this would be a recent regression.

Some info about the computer:
I am running Fedora 23 with gcc 5.3.1 installed (assuming that's what rr's build system uses)

$ cat /proc/version
Linux version 4.4.4-301.fc23.x86_64 (mockbuild@bkernel02.phx2.fedoraproject.org) (gcc version 5.3.1 20151207 (Red Hat 5.3.1-2) (GCC) ) #1 SMP Fri Mar 4 17:42:42 UTC 2016

$ lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                12
On-line CPU(s) list:   0-11
Thread(s) per core:    2
Core(s) per socket:    6
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 63
Model name:            Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Stepping:              2
CPU MHz:               1244.003
CPU max MHz:           3800.0000
CPU min MHz:           1200.0000
BogoMIPS:              6984.35
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              15360K
NUMA node0 CPU(s):     0-11
Flags:                 fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm ida arat epb pln pts dtherm tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid cqm xsaveopt cqm_llc cqm_occup_llc

Not sure what other information could be useful, let me know.

Start by reproducing make check on the reported Fedora 23/Linux environment and inspect the three failing tests: reverse_alarm-no-syscallbuf, checkpoint_async_signal_syscalls_1000-32-no-syscallbuf, and reverse_alarm-32. Compare their failure logs across runs; done means the intermittent cause is identified and make check no longer reports these failures.