According to https://bugreports.qt.io/browse/QTBUG-59094 the dependency entry for libxml2 should be "dev-libs/libxml2[icu]". This probably affects other software embedding chromium as well.
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/proj/qt.git/commit/?id=45d6e682ced55e694ae731a7277cb4c2a6162847 commit 45d6e682ced55e694ae731a7277cb4c2a6162847 Author: Michael Palimaka <kensington@gentoo.org> AuthorDate: 2018-01-15 11:05:59 +0000 Commit: Michael Palimaka <kensington@gentoo.org> CommitDate: 2018-01-15 11:06:13 +0000 dev-qt/qtwebengine: dev-libs/libxml2 must be build with USE="icu" Bug: https://bugs.gentoo.org/644602 Package-Manager: Portage-2.3.14, Repoman-2.3.6 dev-qt/qtwebengine/qtwebengine-5.10.0.ebuild | 2 +- dev-qt/qtwebengine/qtwebengine-5.10.9999.ebuild | 2 +- dev-qt/qtwebengine/qtwebengine-5.9.9999.ebuild | 4 ++-- dev-qt/qtwebengine/qtwebengine-5.9999.ebuild | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-)}
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=4e1d94a283f0a15b6f0c07cb803d9ee140c16f5d commit 4e1d94a283f0a15b6f0c07cb803d9ee140c16f5d Author: Michael Palimaka <kensington@gentoo.org> AuthorDate: 2018-01-15 11:08:05 +0000 Commit: Michael Palimaka <kensington@gentoo.org> CommitDate: 2018-01-15 11:08:22 +0000 dev-qt/qtwebengine: dev-libs/libxml2 must be build with USE="icu" Closes: https://bugs.gentoo.org/644602 Package-Manager: Portage-2.3.14, Repoman-2.3.6 dev-qt/qtwebengine/qtwebengine-5.9.3.ebuild | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
Thanks!