autoconf calls are necessary to build the xhprof php extension in Gentoo.
This is the same situation as with other extensions like
Not sure, if it affects the build process in other distros.
Thanks for the PR, always good to add better error reporting
@sabl0r I had to revert and not run the autoconf for tests to pass on travis - maybe you could wrap this and only execute when it's gentoo ? (see commit 386953407a7721a314a0462f7)