In /usr/include/bits/errno.h there is a line # include <linux/errno.h> but at least on my system the linux directory consists of the single file ".keep" which is empty. I at least got things to compile by changing this line to # include </usr/include/errno.h> I have no idea whether this is a desirable change. Reproducible: Always Steps to Reproduce: 1. 2. 3. Portage 2.0.51.19 (default-linux/amd64/2004.3, gcc-3.4.3-20050110, glibc-2.3.4.20050125-r1, 2.6.10 x86_64) ================================================================= System uname: 2.6.10 x86_64 AMD Opteron(tm) Processor 242 Gentoo Base System version 1.4.16 Python: dev-lang/python-2.3.4-r1 [2.3.4 (#1, Feb 28 2005, 20:08:50)] distcc 2.18.3 x86_64-pc-linux-gnu (protocols 1 and 2) (default port 3632) [disabled] ccache version 2.3 [enabled] dev-lang/python: 2.3.4-r1 sys-devel/autoconf: 2.13, 2.59-r6 sys-devel/automake: 1.5, 1.8.5-r3, 1.6.3, 1.7.9-r1, 1.4_p6, 1.9.4 sys-devel/binutils: 2.15.92.0.2-r1 sys-devel/libtool: 1.5.10-r4 virtual/os-headers: [Not Present] ACCEPT_KEYWORDS="amd64" AUTOCLEAN="yes" CFLAGS="-march=opteron -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.3/env /usr/kde/3.3/share/config /usr/kde/3.3/shutdown /usr/kde/3/share/config /usr/lib/X11/xkb /usr/lib/mozilla/defaults/pref /usr/share/config /usr/share/texmf/dvipdfm/config/ /usr/share/texmf/dvips/config/ /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/texmf/xdvi/ /var/qmail/control" CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d" CXXFLAGS="-march=opteron -O2 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoaddcvs autoconfig ccache distlocks" GENTOO_MIRRORS="http://gentoo.osuosl.org/ http://adelie.polymtl.ca/ ftp://cs.ubishops.ca/pub/gentoo http://csociety-ftp.ecn.purdue.edu/pub/gentoo/ http://gentoo.seren.com/gentoo ftp://linux.cs.lewisu.edu/gentoo/ http://mirror.usu.edu/mirrors/gentoo/" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" SYNC="rsync://rsync.us.gentoo.org/gentoo-portage" USE="X acpi alsa amd64 apache2 atlas bash-completion bcmath bitmap-fonts bonobo cups curl doc emacs esd f77 fam fastcgi fbcon font-server fortran gdbm gif gnome gphoto gpm gstreamer gtk gtk2 icq imlib ipv6 java javascript jikes jp2 jpeg leim libwww lzw lzw-tiff motif mozilla mp3 multilib mysql mysqli ncurses nls ofx oggvorbis opengl oss pam pcmica perl png prp python qt readline samba sasl session shared sharedmem sml2 sockets ssl symlink tcpd tetex threads tiff truetype truetype-fonts type1-fonts usb userlocales xemacs xml2 xmms xpm xprint xrandr xv zlib" Unset: ASFLAGS, CBUILD, CTARGET, LANG, LC_ALL, LDFLAGS, PORTDIR_OVERLAY
you should have kernel-headers installed. That package installs header files in there.
Make sure the linux-headers package is installed.
Please reopen if you have this problems even with linux-headers installed.