[🐛 bug report] Mitsuba2 `gpu_spectral` hangs while loading modules

[jiviteshjain]

Summary

After building successfully, Mitsuba2 (gpu_spectral) hangs midway through loading plugins. The last plugin loaded as per the output is plugins/gaussian.so. No errors are output and the script does not progress for a long time.

System configuration

• Platform: Red Hat EL 7.7 (Linux)
• Compiler: clang 9.0.1
• Python version: Python 3.8.5
• Mitsuba 2 version: 2.2.1
• Compiled variants:
  • scalar_rgb
  • scalar_spectral
  • packet_spectral
  • gpu_spectral

Description

While attempting to render using the mitsuba2 command-line utility with the gpu_spectral variant, the script hangs midway through loading plugins. The last plugin loaded as per the output is plugins/gaussian.so. No progress is made for a reasonably long time afterward, the script keeps prints no output, throws no errors, and does not terminate. CPU variants part of the same compilation work as expected. This is the scene file being rendered.

Steps to reproduce

For bug report, please enumerate the steps to follow in order to reproduce the issue <- [remove this]

1. Compile mitsuba2 using the specifications listed above.
2. Download the scene file from the link above.
3. Run mitsuba -m gpu_spectral -o sample.xml out.exr