The tcl module implementation encourages to
use environment variables like TCL8.5_TM_PATH.
Unfortunately, the naming of variable names in
the "bourne again shell" (bash) is limited to
alpahnumeric characters, including '_'.
Attempts to assign values to a variable with
a name containing a dot-character, as requested
by the "tcl module" functionality, fails if the
assignment is done by a shell command, like
I consider this a severe bug for all those who
are going to prefer the "tcl module" approach when
looking up for packages.
Use '_' instead of '.', i.e. say TCL8_5_TM_PATH
instead of TCL8.5_TM_MODULE.
Possibly that needs only a change of one line in
file tm.tcl and some editing of the documentation.