Today I've found out that: 1) WX_LIBS env var contains LDFLAGS of wxGTK build itself during builds of packages depending on wxGTK:2.8 2) WX_LIBS env var is populated from the output of "wx-config --libs" command 3) wx-config script is compiled from wx-config.in during the build of wxGTK 4) wx-config.in indeed contains a line (1209) that hardcodes LDFLAGS into the wx-config script 5) this bug has been fixed upstream (http://trac.wxwidgets.org/changeset/62459/svn-wx), but not included into the 2.8 branch 6) the fix has merge conflicts if applied to the current version of wxGTK:2.8 For me this bug means numerous build failures. Quick and dirty fix I did was to nuke "@LDFLAGS@" and replace it with "-pthread" as seen in wx-config-3.0
By now 2.8 is on the way out hopefully soon, sorry. I understand that 3.0 is fine, so marking as OBSOLETE accordingly, as there's no point to spend time on this for 2.8 anymore.