| Package | “custom-optimization” Flag Description | 
|---|---|
| dev-lang/jsonnet | Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported) | 
| dev-util/kernelshark | Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS | 
| www-client/seamonkey | Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported) |