Docker compose sets HSA_OVERRIDE_GFX_VERSION=${HSA_OVERRIDE_GFX_VERSION:-}
which results in an empty string when not provided. An empty string is
not the same as unset - ROCm treats it as 'force-empty' and no GPU is
detected, even natively supported ones (e.g. gfx1201 / RX 9070 on ROCm 7.2).
Pop the env var when it is empty, before torch loads, so ROCm auto-detects
the GPU correctly.
Tested on RX 9070 (gfx1201) with ROCm 7.2 and PyTorch 2.12.1+rocm7.2.
