I can open this as a github issue too but I'm thinking this is just user error. Also forgive me I'm not super familiar with C++.
I want to use PBRT to model atomic emission from fusion plasmas so I want to use the spectral renderer. I can get the scenes in "pbrt-v4-volumes" to render using a gpu. These scenes are all RGB. I can get a test case spectral scene I made to render using the CPU but when I try the same scene with a GPU I get a core dump.
When I build it debug mode both CPU and GPU spectral renders crash so I not sure the output is meaningful? Is there an example of a known working gpu spectral renderer? All of the examples I've seen are RGB.