This is downstream bug report:
http://bugs.gentoo.org/show_bug.cgi?id=286375

You can read full build log in:
http://bugs.gentoo.org/attachment.cgi?id=220325&action=view

tests fail when vte is built with --enable-gtk-doc with the following:

Making check in doc
make[1]: Entering directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc'
Making check in reference
make[2]: Entering directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc/reference'
make  check-TESTS
make[3]: Entering directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc/reference'
make[4]: Entering directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc/reference'
make[4]: Nothing to be done for `vte-undeclared.txt'.
make[4]: Nothing to be done for `vte-unused.txt'.
make[4]: Leaving directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc/reference'
Unused documentated symbols:
VTE_BOLD_FG
VTE_CUR_BG
VTE_DEF_BG
VTE_DEF_FG
VTE_DEF_HL
VTE_DIM_FG
VTE_PALETTE_SIZE
VTE_STREAM_GET_CLASS
VTE_TYPE_FILE_STREAM
VTE_TYPE_STREAM
VteCell
VteCellAttr
VteFileStream
VteFileStreamClass
VteRowAttr
VteRowData
VteStream
VteStreamClass
Incomplete or undocumented symbols:
99% symbol docs coverage.
180 symbols documented.
0 symbols incomplete.
1 not documented.


VteTerminal::move-window


FAIL: check-doc-coverage.sh
Checking documentation for incorrect syntax
PASS: check-doc-syntax.sh
====================================================================
1 of 2 tests failed
Please report to http://bugzilla.gnome.org/enter_bug.cgi?product=vte
====================================================================
make[3]: *** [check-TESTS] Error 1
make[3]: Leaving directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc/reference'
make[2]: *** [check-am] Error 2
make[2]: Leaving directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc/reference'
make[1]: *** [check-recursive] Error 1
make[1]: Leaving directory `/var/tmp/portage/x11-libs/vte-0.22.5/work/vte-0.22.5/doc'
make: *** [check-recursive] Error 1

Thanks a lot