Occasional crash on android device, somehow related to cubemap

We are facing occasional crash on android device and it is hard to reproduce. We track the crash on Fabric and it looks like this:
r0 abb2cc7c r1 00000007 r2 00000000 r3 00000000
r4 ac868688 r5 abb2ba90 r6 abd668f0 r7 ffffe97c
r8 000011ec r9 00000001 sl 00000002 fp 00000002
ip 0000002a sp 58555790 lr ffffffff pc 573a3dec cpsr 50343855

at libunity.0050ddec(Unknown Source)
at libunity.002190d8(Unknown Source)
at libunity.004aceec(Unknown Source)
at libunity.004acd7c(Unknown Source)
at libunity.004af3d0(Unknown Source)
at libunity.004b0658(Unknown Source)
at libunity.00174c10(Unknown Source)
at libunity.001753d8(Unknown Source)
at libunity.003317d0(Unknown Source)
at libunity.002e5980(Unknown Source)
at libunity.0053c4d8(Unknown Source)
at libunity.0053eda8(Unknown Source)
at libdvm.dvmPlatformInvoke(dvmPlatformInvoke:112)
at libdvm.dvmCallJNIMethod(unsigned int const*, JValue*, Method const*, Thread*)(dvmCallJNIMethod:398)
at libdvm.0006e920(Unknown Source)
at libdvm.dvmMterpStd(Thread*)(dvmMterpStd:76)
at libdvm.dvmInterpret(Thread*, Method const*, JValue*)(dvmInterpret:184)
at libdvm.dvmCallMethodV(Thread*, Method const*, Object*, bool, JValue*, std::__va_list)(dvmCallMethodV:338)
at libdvm.dvmCallMethod(Thread*, Method const*, Object*, JValue*, ...)(dvmCallMethod:20)
at libdvm.0007f4cb(Unknown Source)
at libc.__thread_entry(__thread_entry:72)
at libc.pthread_create(pthread_create:240)

I am trying to parse these message to some readable method name, and then it looks something like this:
SuiteGameObjectCreationTests::TestCreateSphereTest::RunImpl() const
PPtr<Cubemap>:perator Cubemap*() const
SuiteFloatConversionTests::TestFloatConversionTests_FloatToHalf::RunImpl() const
SuiteFloatConversionTests::TestFloatConversionTests_FloatToHalf::RunImpl() const
SuiteFloatConversionTests::TestFloatConversion_Repeat::RunImpl() const
SuiteGradientTests::TestSetAlphaKeys_WithMultipleKeys_SortsThemBasedOnTime::RunImpl() const
dynamic_array<GameObject::ComponentPair, 4u>:ush_back(GameObject::ComponentPair const&)
GameObject::AddComponentInternal(GameObject&, Unity::Component&)
CubemapArray::ExtractImageImpl(ImageReference*, ImageReference::BlitMode, bool, int) const
SuiteStringTests::Testend_ReturnsIteratorBehindLastChar_stdstring::~Testend_ReturnsIteratorBehindLastChar_stdstring()

Just from these methods' name, it looks like the crash is from cubemap problem (which is the only meaningful stuff I can find from them), but I am pretty sure I am not using any cubemap in the project. I am confused what should I debug this problem next?

The Unity version we are using is 5.5.0p2

 

Anybody can give me some hints?