I wondered if there has been any change since this report: https://lists.gnu.org/archive/html/bug-gnulib/2008-08/msg00209.html
The issue is that on Solaris 10 and Solaris 11, wcwidth returns 2 instead of 1 for some characters, for example, opening double quote “. Some of these characters are listed as "ambiguous" under http://unicode.org/reports/tr11-2/, but having different results on different systems makes a test suite almost useless on at least one of the systems. Would it be possible for gnulib to override the system wcwidth if it has unusual return values? wcwidth is used by the texi2any program in Texinfo to output to monospaced plain text for use in a terminal emulator. It is used for wrapping lines.