After installing dev-embedded/arduino the following emerge complains that world file needs to be checked (with emaint). Reason is crossdev/avr-gcc, -binutils and glibc missing. I tracked this down to the arduino-ebuild. It is not necessary to install a crossdev toolchain. It is absolutely sufficient to install a board from the board manager in the UI (menu tools). This ends up in user's home directory. See https://support.arduino.cc/hc/en-us/articles/360016119519-How-to-add-boards-in-the-board-manager for reference. Reproducible: Always Steps to Reproduce: 1. emerge dev-embedded/arduino 2. run another emerge Actual Results: Second emerge complains about missing crossdev packages. Expected Results: Subsequent emerges don't complain. It'd be great if this were supported by a USE flag for the ebuild that is not enabled by default. And with the USE-flag crossdev will be installed, too. Should point out the extra time then. Also mind that the repository for crossdev has to be created through eselect for ease of use: https://wiki.gentoo.org/wiki/Creating_an_ebuild_repository. The crossdev wiki page outlines the pre-eselect step-by-step variant: https://wiki.gentoo.org/wiki/Crossdev
