Чтобы пересобрать пакет с возможностями отладки, я переопределяю CFLAGS и USE
USE=debug CFLAGS="-march=core2 -O2 -pipe --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144 -msse4.1 -ggdb" CXXFLAGS="$CFLAGS" emerge <пакет>
./configure --prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --libdir=/usr/lib64 --disable-dependency-tracking --enable-debug --without-libgeoip --without-libproxy --without-libunique --without-libappindicator --disable-gtk3
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x86_64-pc-linux-gnu-gcc -DHAVE_CONFIG_H -I. -I.. --pedantic -Wall -Wno-format -Wno-overflow -I.. -DTRGLICENSE=\""/usr/share/doc/transmission-remote-gtk-1.0/COPYING"\" -pthread -I/usr/include/json-glib-1.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -pthread -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -pthread -I/usr/include/gtk-2.0 -I/usr/lib64/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng15 -I/usr/include/libdrm -pthread -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -pthread -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/libpng15 -march=core2 -O2 -pipe --param l1-cache-size=32 --param l1-cache-line-size=64 --param l2-cache-size=6144 -msse4.1 -ggdb -c remote-exec.c
CC trg-gtk-app.o