On 13.03.2012 13:58, Thufir Hawat wrote: > which or where tcl and tk does arcadia require? Is this a gem which I > install, or a package from synaptic? In either case, which one > specifically? There are so many variants. [...] > thufir@caladan:~$ rvm -v [...] > Arcadia require ruby-tk extension You already got a lot of useful responses, but here's my guess: when you use RVM you basically build Ruy yourself. You did install the TCL/TK packages *after* your installed Ruby, my guess is you need them to have properly installed *before* you build Ruby; i.e. Ruby requires them to be present during the build process. Short: now that you have the TCL/TK packages (and their -dev variants probbably) installed, reinstall Ruby via rvm so it picks them up. I've never used TCL/TK but I have similar problems when using rvm on a new machine and I forget to install e.g. libreadline-dev ; I end up with a non-working IRB, which requires that the libreadline-dev package is available at the time I install/build Ruby via rvm (at least this was the case in the past). HTH, - Markus