Hallo. It seems that something was changed in Ruby that makes texexec --mptex not working with some Unicode letters, e.g. rcaron. This file compiles all right with texexec --mptex: beginfig(1); label(textext("a"),origin); endfig; end. However, when I change "a" to "ř" (unicode for rcaron or \v{r}), it failes with this complaint: /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/switch.rb:21: Use RbConfig instead of obsolete and deprecated Config. /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/tex.rb:1982:in `doruntexmp': invalid byte sequence in US-ASCII (ArgumentError) from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/tex.rb:1525:in `runtexmp' from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/tex.rb:1087:in `block in processmptex' from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/tex.rb:1084:in `each' from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/tex.rb:1084:in `processmptex' from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/texexec.rb:76:in `mptex' from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/base/switch.rb:133:in `execute' from /home/qasar/programy/context.beta/tex/texmf-context/scripts/context/ruby/texexec.rb:791:in `<main>' It crashes both with the latest beta (downloaded some minutes ago) and with the latest stable (downloaded yesterday). It crashes also with the stable instalation that was working previously. Since it worked properly with Ubuntu 12.04 and is not working (with the same ConTeXt installation) with Ubuntu 12.10, an explanation might be a change in Ruby that makes some ConTeXt code invalid. I'm using * Ubuntu 12.10 (Linux) * Ruby ruby 1.9.3p194 (2012-04-20 revision 35410) [i686-linux] * texexec * ConTeXt standalone (minimal) distribution from the ConTeXt Garden, latest beta, latest stable and some older version that was previously working. Since I'm using it to create my teaching slides, I would really appreciate if you could make some patch (or help me go around somehow). Best wishes, Michal P.S. I apologize if the bug is known already; I haven't found it in the mailing list.