I have a chroot for building binaries for a netbook. I keep it fairly clean between updates (and run emerge -cqp --with-bdeps=n). To update qt-creator today, it wanted to pull in doxygen with +qt4. It failed to emerge doxygen stating that it failed to configure with qt4 support, but reading the log it seemed to be that it was missing bison. I did emerge -1 bison and it fixed it for me, so something (either doxygen or lower on the depgraph) must be missing a bison dep. I hope this helps. Reproducible: Always
Please attach build.log with failure. Also virtual/yacc dependency must be used now instead of bison one.
Created attachment 284025 [details] build.log as requested
*doxygen-1.7.6.1 (14 Feb 2012) 14 Feb 2012; Kacper Kowalik <xarthisius@gentoo.org> +doxygen-1.7.6.1.ebuild, metadata.xml: Version bump: EAPI4, reorder vars, initial support for LINGUAS, use 'dot' instead of 'nodot', add missing dependencies on perl and bison (fixes bug #399349 by bay), respect CC and CXX, call eqmake4 for doxywizard, always use emake, simplify latex+doc logic. Add myself as maintainer.