My list of use-flags for opencv: > contrib contribcvv contribdnn contribfreetype contribhdf contribsfm contribxfeatures2d cuda download eigen features2d ffmpeg gdal gflags glog gphoto2 gstreamer jpeg jpeg2k lapack opencl opencvapps openexr opengl openmp png python qt5 tesseract testprograms threads tiff v4l vaapi vtk webp xine Temp files of opencv-4.5.4 has more than 2.5Gb. I use 1G tmpfs as temporary dir: PORTAGE_TMPDIR=/tmp. So, in my case compilation failed and I need to do per-package correction of PORTAGE_TMPDIR variable. Problem: I detect, that opencv build process need more disk space, only after failed compilation and after lose CPU time and my time. Usage of CHECKREQS_DISK_BUILD variable in ebuild allow to quickly detect packages, which needs more disk space. Please, add minimal disk size requirement to ebuild file. Something like this: > CHECKREQS_DISK_BUILD="3G" or like this: > for use_flag in ${IUSE}; do > if usex ${use_flag} in dnnsamples download contrib <?etc?>; do > CHECKREQS_DISK_BUILD="3G" > fi > done Reproducible: Always