File: /etc/portage/make.bashrc

Config file sourced by bash build environment. Contains the build-time / bash environment variables from /etc/make.conf, such as CHOST, CFLAGS, CXXFLAGS, LDFLAGS, MAKEOPTS, INPUT_DEVICES, VIDEO_CARDS, etc. Allows full bash syntax (e.g., conditional expressions). Can include package-specific build-time configuration options not covered by USE flags (i.e., over-ride defaults assumed in ebuild or package defaults).

Directory: /etc/portage/make.bashrc.d/$CATEGORY/$PN

Config files sourced by bash build environment. Contains package-specific over-rides of make.bashrc; zero or one file per package, containing multiple variables. Replaces /etc/portage/env/$CATEGORY/$PN. Allows full bash syntax (e.g., conditional expressions).