Issue with SPIR-V kernels compiled with debug symbols

[tneval]

I'm having problems with SPIR-V kernels that have added debug symbols:

$ clang -fsycl ex.cpp -o ex -g

$ SYCL_DUMP_IMAGES=1 ./ex

$ spirv-val sycl_spir64.spv 
error: line 1451: ID 474[%474] has not been defined
  %484 = OpExtInst %void %2 10 %225 %uint_2 %478 %uint_16 %uint_0 %474 %485 %uint_32 %uint_32768 %488 %495

Not sure if this validation error is related, but program itself also fails to run.
I'm using PoCL as OpenCL backend for DPC++, which works fine without debugging symbols.

Any ideas how to proceed with this?

Thanks.